[Search] Unify data.search plugin

[lizozom]

_async_search is available with the Free license since 7.11
This means we can unify the data.search plugin and simplify the code.

• Unify search interceptor [Search] Unify search plugin step 2 — Search Interceptor #97845
• Deprecate TimeoutErrorMode.UPGRADE [Search] Unify search plugin step 2 — Search Interceptor #97845
• Remove the defaultStrategy override [Search] Unify search plugin step 1 #95811
• Move async search strategy to data [Search] Unify search plugin step 1 #95811
• Move EQL search strategy to data [Search] Unify search plugin step 1 #95811
• Split rollups out of async search strategy [Search] Unify search plugin step 3 — Rollup search strategy #98122
• Depends on moving security and taskManager out of x-pack (at this point this hasn't been prioritised)
  • Move search sessions code to data [data.search] remove data_enhanced #119321
  • Deprecate data.__enhance [data.search] remove data_enhanced #119321
• Update all READMEs and docs with these changes

[elasticmachine]

Pinging @elastic/kibana-app-services (Team:AppServices)

[lizozom]

@gmmorris @legrego do you have any ETA for when taskManager and security plugins will be moved out of xpack?

[legrego]

@lizozom portions of the security plugin will always live in xpack, because they are licensed features. There is some functionality that we can move out, but we don't have an ETA on that work yet.

It's not something that we've identified as a priority, as it wasn't blocking any critical work that we were aware of, and our roadmap is already pretty full. Do you have a need to complete this work by a specific release?

[gmmorris]

@gmmorris @legrego do you have any ETA for when taskManager and security plugins will be moved out of xpack?

None at all for TM.
@mikecote might know better than me, but I wasn't aware of this being on the books at all.

Is this blocking you?

[mikecote]

None at all for TM.
@mikecote might know better than me, but I wasn't aware of this being on the books at all.

There have been prior discussions to move Task Manager to OSS but nothing further. I'll ping people from this thread on the other issue.

[lukasolson]

This is blocked on #104152.

[lukasolson]

The remainder of this work has been unblocked by #107432.

[Dosant]

Close in favor of #119321