What changed?

Remove raw history support in client

Why?

History is stored as Thrift encoded binary. Sending raw history in Thrift will no longer be supported in V4

How did you test it?

Unit Test

What changed?

added client entities that maps 1:1 with thrift (generated from a generator)
added BaseError, which is a catchall similar to TException.
added mappers to transform Proto to client entities. (mostly copied from thrift mappers)
added IWorkflowServiceV4 which is exactly same as IWorkflowService except for it's using the client entities.
added WorkflowServiceGrpc that implements the V4 interface
Plan

new V4 interface with new entities < This PR
replace all pointers to V4 in one go (Should be import change only)
Why?

Thrift deprecation work

How did you test it?

Unit Test on mappers from ClientObjects to ProtoObjects

What changed?

replace internal TasklistKind entity with thrift one directly, which will be replaced with V4 entity eventually
Why?

TasklistKind is an internal entity introduced earlier. With V4, we already have this and thus do not need extra ones.