[Core deprecations service] Add support for deprecation title

[alisonelizabeth]

It's come up a few times that the title of a Kibana deprecation isn't very helpful. Most recently from the docs team here: #97159 (comment). The title is currently derived in Upgrade Assistant using the domainId, e.g., "''domain_id' is using a deprecated feature".

I think it's warranted to update the deprecations service to enforce the consumer provide a title and description.

interface DeprecationInfo {
  ... 
  title: string;
  message: string;
  ....
}

[elasticmachine]

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

[alisonelizabeth]

Hi @Bamieh! Is this something core will still be able to implement? I think it will greatly improve the user experience.

[Bamieh]

@alisonelizabeth I'll work with you this week to fully flush this issue so we can get started on it

[cjcenizal]

@Bamieh FYI #109166 is blocked on this. In addition to the screenshot Alison shared above, the goal is also to enable a UI like this one:

[Bamieh]

@cjcenizal Core prioratized this task for this sprint and I've started working on it today.