Refactor and simplify aggregation implementers

[idegtiarenko]

This change refactors aggregation implementers by:

• removing unused methods in Types and replacing duplicated code with a common implementation
• replacing type derivation with a corresponding aggState (that encapsulates information related to SingleState and GroupingState) and aggParam (encapsulates parameter to the aggregation function) classes.

This refactoring is intended to:

• make it simpler to add more than a single agg parameter in the future (for use cases such as first(column, @timestamp) and topN(column, count, ASC/DECK, @timestamp)
• reduce Method dependencies to make it easier to use requireMethod to spell expected method signatures.

This does not cause any changes in the generated code.

[elasticsearchmachine]

Pinging @elastic/es-analytical-engine (Team:Analytics)

[nik9000]

Sure.

[elasticsearchmachine]

💔 Backport failed

Status	Branch	Result
❌	9.0	Commit could not be cherrypicked due to conflicts
❌	8.x	Commit could not be cherrypicked due to conflicts

You can use sqren/backport to manually backport by running backport --upstream elastic/elasticsearch --pr 121818

[idegtiarenko]

The backport is failing as both 8.x and 9.0 do not have following back-ported yet: #119889