[expressions] Improved semantics on all functions

[streamich]

Currently some of our functions accept JSON blobs as parameters which prevents other teams from reusing these functions efficiently. We need to do this cleanup to make functions available inside lens and canvas and to enable moving these functions to the server side.

• esaggs improved semantics for esaggs function #61768
  • Cleanup on some specific agg parameters [data.search.aggs]: Create expression functions for object types used in agg params #67908
• kibana_context improved semantics for kibana_context function #65988
• kibana

chart functions:

• tsvb (this should not be reusable, and we even don't validate the payload explicitly anymore in the backend: Enable prototype pollution protection in TSVB #78908 so we agreed to not make this explicit in the tsvb function)
• vega
• timelion_vis
• kibana_table

Since the following are planned to be removed until 8.0 we're no longer going to migrate them:

• vislib
• kibana_pie
• tilemap
• regionmap

Parent issue: #46909

[elasticmachine]

Pinging @elastic/kibana-app-arch

[ppisljar]

removing this as majority of work is finished and we have issues open for the remaining items