[Search] Telemetry on async search/search sessions

[lukasolson]

Part of #61738

In the context of resiliency/retry-ability, we should collect the following:

• Shard failures
• Request failures
• Request timeouts (elasticsearch.requestTimeout)

In the context of user actions, we should collect the following:

• Time between initiating query and sending to background

In context of search session management UX:

• Extend session
• Cancel session
• Restore session
• Reload session

In the context of Background Search Service

• Max amount of sessions in memory
• Amount of sessions created (Calls to trackId with unique sessionId)
• Amount of sessions saved (Calls to store)
• Amount of sessions retrieved (Calls to get, not distinct)
• Amount of sessions dropped due to errors
• Amount of sessions expired
• Amount of saved object update retries

[elasticmachine]

Pinging @elastic/kibana-app-arch (Team:AppArch)