[deprecations] Expose docLinks in the ConfigDeprecationContext

[lukeelmers]

As discussed in #112221, we'd like to make it as easy as possible for a ConfigDeprecationProvider to provide links to users to relevant documentation for addressing deprecated configs.

In #114065 we exposed the current branch to the ConfigDeprecationProvider so that plugins could construct their own doc links manually. But now that #95389 has been addressed and the docLinks service is exposed on the server, a more convenient approach would be to provide the docLinks directly in the ConfigDeprecationContext:

kibana/packages/kbn-config/src/deprecation/types.ts

Lines 70 to 80 in 5dbe273

	/**
	* Deprecation context provided to {@link ConfigDeprecation | config deprecations}
	*
	* @public
	*/
	export interface ConfigDeprecationContext {
	/** The current Kibana version, e.g `7.16.1`, `8.0.0` */
	version: string;
	/** The current Kibana branch, e.g `7.x`, `7.16`, `master` */
	branch: string;
	}

This way plugins can leverage the existing doclinks infrastructure instead of building their own urls manually.

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)