[Feature Request] Support user metadata

[cretz]

Describe the solution you'd like

See temporalio/features#486. Specifically, after temporalio/sdk-core#830:

• Accept optional "static summary " and "static details" on all ways to start a workflow (start, signal with start, schedule, and child workflow) and populate user metadata with them
• Accept optional "summary" when creating timers and populate user metadata with it
• Accept optional "summary" when creating activities and populate user metadata with it
• Handle __temporal_workflow_metadata query (see features issue and Experimental user metadata and workflow metadata query support sdk-go#1597)
• Mark experimental

[aluksidadi]

Hey folks, excited about the PR, any update on when that'll be merged? Thanks!