Allow providing Group Provisioning via `occ user_oidc:provider`

Currently it can be set via occ config:app:set, but that's bulky and requires you to know the auto-generated ID of your provider. If it could be set via user_oidc:provider, like most of the other options can be, it would make setting up OIDC Providers much more convenient.

For what it's worth, if people are looking for an automated solution to getting the ID from a given provider name:

PROVIDER_NAME=Authelia
PROVIDER_ID=$(./occ user_oidc:provider --output json "$PROVIDER_NAME" | python -c 'import json; p = json.loads(input()); print(p["id"])')
./occ \
  config:app:set \
  user_oidc \
  "provider-${PROVIDER_ID}-groupProvisioning" \
  --value 1

Start with the occ user_oidc:provider command and compare its existing options with the config:app:set path for provider-${PROVIDER_ID}-groupProvisioning. The change is done when group provisioning can be set through user_oidc:provider using a provider name, with behavior equivalent to the current configuration command.