[Breaking change] Add deprecation from removed proxyConfig and proxyFilter Console settings

[cjcenizal]

Change description

Which release will ship the breaking change?

8.0

Is this a Kibana or Elasticsearch breaking change?

Kibana breaking change

Describe the change. How will it manifest to users?

See #39494 for more info. Requires more research.

How many users will be affected?

These settings have been deprecated and undocumented since before 5.4, so it's unlikely many people are still using them.

Are there any edge cases?

No.

[For Kibana deprecations] Can the change be registered with the Kibana deprecation service?

Yes, we can detect if these settings are in use and advise the user to migrate to the standard SSL settings.

Test Data

Create settings per https://www.elastic.co/guide/en/kibana/5.0/configuring-console.html.

[elasticmachine]

Pinging @elastic/kibana-stack-management (Team:Stack Management)

[cjcenizal]

Fixed by #113555