security/acme-client: Add DNSAPI for Wix.com

Important notices
Before you add a new report, we ask you kindly to acknowledge the following:

• I have read the contributing guide lines at https://github.com/opnsense/plugins/blob/master/CONTRIBUTING.md
• I have searched the existing issues, open and closed, and I'm convinced that mine is new.
• When the request is meant for an existing plugin, I've added its name to the title.

Is your feature request related to a problem? Please describe.
Please add DNSAPI support for Wix.com

Describe the solution you'd like
Use the code provided here, filename dns_wix.sh :

#!/bin/bash
# shellcheck disable=SC2034

dns_wix_info='WIX
Site: wix.com
Options:
  WIX_API_TOKEN API Token
  WIX_API_ID API ID
'

# DNS API DEV-Guide: https://github-wiki-see.page/m/acmesh-official/acme.sh/wiki/DNS-API-Dev-Guide
# WIX API DEV-Guide: https://dev.wix.com/docs/api-reference/account-level/domains/domain-dns/get-dns-zone

WIX_API="https://www.wixapis.com/domains/v1"


# Usage: add  _acme-challenge.www.domain.com   "XKrxpRBosdIKFzxW_CT3KLZNf6q0HG9i01zxXp5CPBs"
# Used to add txt record
dns_wix_add()
{
	# Step 1: Get full domain and the txt record
	FULLDOMAIN=$1
	TXTVALUE=$2

	# Step 2: The credentials such as username, password, api key or api token etc,
	# must be saved so that acme.sh can renew the cert automatically in future.
	# It will reuse the credentials automatically.
	WIX_API_ID="${WIX_API_ID:-$(_readaccountconf_mutable WIX_API_ID)}"
	WIX_API_TOKEN="${WIX_API_TOKEN:-$(_readaccountconf_mutable WIX_API_TOKEN)}"
	if [ -z "${WIX_API_ID}" ] || [ -z "${WIX_API_TOKEN}" ]; then
		WIX_API_ID=""
		WIX_API_TOKEN=""
		_err "You don't specify wix api key and email yet."
		_err "Please create your key and try again."
		return 1
	fi

	# save the credentials to the account conf file.
	_saveaccountconf_mutable WIX_API_ID "${WIX_API_ID}"
	_saveaccountconf_mutable WIX_API_TOKEN "${WIX_API_TOKEN}"

	# Step 3: Detect which part is my root zone
	_debug "dns_wix_add: First detect the root zone"
	if ! _get_root "${FULLDOMAIN}"; then
		_err "invalid domain"
		return 1
	fi
	_debug _domain_id "${_domain_id}"
	_debug _sub_domain "${_sub_domain}"
	_debug _domain "${_domain}"

	_debug "Getting txt records"
	_wix_rest GET "dns-zones/${_domain_id}"

	if test "$?" != "0" -o -z "${RESPONSE}"; then
		_err "Error"
		return 1
	fi

	# Step 4: Call your dns api to add txt record

	# For wildcard cert, the main root domain and the wildcard domain have the same txt subdomain name, so
	# we can not use updating anymore.

	_info "Adding record"
	if _wix_rest PATCH "dns-zones/${_domain_id}" "{\"domainName\": \"${_domain_id}\", \"additions\": [{\"type\":\"TXT\",\"hostName\":\"${FULLDOMAIN}\",\"values\":[\"${TXTVALUE}\"],\"ttl\":120}]}"; then
		if _contains "${RESPONSE}" "${TXTVALUE}"; then
			_info "Added, OK"
			return 0
		elif _contains "${RESPONSE}" "resource already exists"; then
			_info "Already exists, OK"
			return 0
		elif _contains "${RESPONSE}" "domainName is not a valid hostname"; then
			_err "invalid request, response \"${RESPONSE}\"."
			return 1
		else
			_err "Add txt record error, response \"${RESPONSE}\"."
			return 1
		fi
	fi

	_err "Add txt record error, http request failed."
	return 1
}

# Usage: fulldomain txtvalue
# Used to remove the txt record after validation
#  fulldomain txtvalue
dns_wix_rm()
{
	# Step 1: Get full domain and the txt record
	FULLDOMAIN=$1
	TXTVALUE=$2

	# Step 2: The credentials such as username, password, api key or api token etc
	WIX_API_ID="${WIX_API_ID:-$(_readaccountconf_mutable WIX_API_ID)}"
	WIX_API_TOKEN="${WIX_API_TOKEN:-$(_readaccountconf_mutable WIX_API_TOKEN)}"

	# Step 3: Detect which part is my root zone
	_debug "dns_wix_rm: First detect the root zone"
	if ! _get_root "${FULLDOMAIN}"; then
		_err "invalid domain"
		return 1
	fi

	_debug _domain_id "${_domain_id}"
	_debug _sub_domain "${_sub_domain}"
	_debug _domain "${_domain}"

	_debug "Getting txt records"
	_wix_rest GET "dns-zones/${_domain}"

	if test "$?" != "0" -o -z "${RESPONSE}"; then
		_err "Error"
		return 1
	fi

	_debug response "${RESPONSE}"

	# Step 5: Call dns api to delete txt record
	if _wix_rest PATCH "dns-zones/${_domain_id}" "{\"domainName\": \"${_domain_id}\", \"deletions\": [{\"type\":\"TXT\",\"hostName\":\"${FULLDOMAIN}\",\"values\":[\"${TXTVALUE}\"]}]}"; then

		if _contains "${RESPONSE}" "domainName is not a valid hostname"; then
			_err "domainName is not a valid hostname"
			return 1
		fi

		_info "TXT record removed."
		return 0
	fi

	_err "Delete txt record error, http request failed, response \"${RESPONSE}\"."
	return 1
}


####################  Private functions below ##################################
# Detect which part is your root zone
# The full domain could be in either one of the following formats:
#
#    _acme-challenge.www.example.com
#    _acme-challenge.example.com
#    _acme-challenge.example.co.uk
#    _acme-challenge.www.example.co.uk
#    _acme-challenge.sub1.sub2.www.example.co.uk
#    sub1.sub2.example.co.uk
#
#_acme-challenge.www.domain.com
#returns
# _domain_id=domain.com from "id":"domain.com"
# _sub_domain=www.domain.com
# _domain=domain.com
#
_get_root()
{
	DOMAIN=$1
	i=1
	p=1

	_debug2 "wix: _get_root"
	while true; do
		HOST=$(printf "%s" "${DOMAIN}" | cut -d . -f "$i"-100)
		_debug HOST "${HOST}"
		if test -z "${HOST}"; then
			# not valid
			_err "_get_root: empty host not valid"
			return 1
		fi

		if ! _wix_rest GET "dns-zones/${HOST}"; then
			_err "_get_root: no response"
			return 1
		fi
		_debug2 _get_root: response "${RESPONSE}"

		if _contains "${RESPONSE}" "\"domainName\":\"${HOST}\""; then
			_domain_id=$(echo "${RESPONSE}" | _egrep_o "\"id\": *\"[^\"]*\"" | cut -d : -f 2 | tr -d \" | tr -d " ")
			_sub_domain=$(printf "%s" "${HOST}" | cut -d . -f 1-"$p")
			_domain=${HOST}
			return 0
		fi

		p=$i
		i=$(_math "$i" + 1)
	done

	return 1
}

_wix_rest()
{
	METHOD=$1
	ENDPOINT="$2"
	DATA="$3"
	_debug "${ENDPOINT}"

	#export _H1="Content-Type: application/json"
	export _H1="wix-account-id: ${WIX_API_ID}"
	export _H2="Authorization: ${WIX_API_TOKEN}"

	if test "${METHOD}" != "GET"; then
		_debug data "${DATA}"
		RESPONSE="$(_post "${DATA}" "${WIX_API}/${ENDPOINT}" "" "${METHOD}" application/json)"
	else
		RESPONSE="$(_get "${WIX_API}/${ENDPOINT}")"
	fi

	if test "$?" != "0"; then
		_err "error ${ENDPOINT}"
		return 1
	fi

	_debug2 response "${RESPONSE}"
	return 0
}

Start in the acme-client plugin and use the supplied dns_wix.sh as the implementation reference. Verify that Wix API credentials, DNS TXT-record addition, root-zone discovery, and removal work through the existing plugin flow; done means the Wix DNSAPI is integrated and can complete certificate validation cleanup.