Input screen should show some sort of preview of the input address

## What?

When you are on the input page it should show you the expected (perhaps default) address that you need to be sending your logs to. On Global inputs it could use the external URI and on local inputs the published URI. Ideally, it could even show it in multiple formats, or the format most common for that input.

Example (for a standard input, gelf raw etc)
graylog.company.com:12201
http://graylog.company.com:12201/gelf

(syslog)
address: graylog.company.com port: 1514 type: TCP

(beats)
output.logstash:
hosts: ["graylog.company.com:5044"]

## Why?

For new users it's not clear where you need to send your logs, people get confused about sending it to the input vs the API, and then some are downright confusing. the GELF http input for example required /gelf added to the end, it doesn't say that anywhere in the product, or give you and option to change that, so you would have no way of knowing that's required.

## Your Environment

* Graylog Version:
* OpenSearch Version:
* MongoDB Version:
* Operating System:
* Browser version: