Fix thread safety issues in test Client

Support no-op map transactions

Invalidate/update map cache on Transaction Commit()

Add transaction API for map primitive

Ensure options are passed through transcoding interfaces

Use scalar encode/decode functions in map/indexedmap transcoders

Remove base64 encoding in map keys

Fix thread safety on reads of IndexedMap cache

Improve primitive caches to avoid race conditions following events

Add GetIndex to cached IndexedMap