Plugins to support controlling multiple configuration points at once

Is your feature request related to a problem? Please describe.

Users often need to configure a number of things in order to support certain systems. For instance, all workflows at Company X might need to register a dataconverter, customize the sandbox, register a set of activities, etc.

Describe the solution you'd like

A plugin model to allow configuring all these points at once.

# In client (would rather have this on client.Interceptor, but people
# are concerned with the name "interceptor" though I prefer it)
class Plugin:
  # NOTE: ClientConnectConfig could help at https://github.com/temporalio/sdk-python/pull/895
  async def connect_client(self, config: ClientConnectConfig, next: Plugin) -> Client:
    # Default impl calls next
	  
  def create_client(self, config: ClientConfig, next: Plugin) -> Client:
    # Default impl calls next
    
# In worker (would rather have this on worker.Interceptor, but people
# are concerned with the name "interceptor" though I prefer it)
class Plugin:
  def create_worker(self, config: WorkerConfig, next: Plugin) -> Worker:
    # Default impl calls next
    
  async def run_worker(self, worker: Worker, next: Plugin) -> None:
	  # Default impl calls next

For example:

class MyPlugin(client.Plugin, worker.Plugin, client.Interceptor, worker.Interceptor):
  def create_client(self, config: ClientCreateConfig, next: Plugin) -> Client:
    # Say you want to set data converter and interceptor
    config["data_converter"] = MyDataConverter()
    config["interceptors"].append(self)
    return super().create_client(config, next)
    
  def create_worker(self, config: WorkerCreateConfig, next: Plugin) -> Worker:
    # Say you want an activity
    config["activities"].append(MyActivity())
    return super().create_worker(config, next)
    
  async def run_worker(self, worker: Worker, next: Plugin) -> None:
    try:
      await super().run_worker(worker, next)
    finally:
      # Say you want to do something on worker shutdown
      do_some_cleanup()
      
  def intercept_activity(self, next: ActivityInboundInterceptor) -> ActivityInboundInterceptor:
    # Say you want to intercept activities
    return MyActivityInterceptor(next)

Additional context

Per-SDK Tickets

• Go - https://github.com/temporalio/sdk-go/issues/2020
• Java - https://github.com/temporalio/sdk-java/issues/2626
• Core - N/A
• TypeScript - https://github.com/temporalio/sdk-typescript/issues/1764
• Python - https://github.com/temporalio/sdk-python/issues/950 and https://github.com/temporalio/sdk-python/pull/1011
• .NET - https://github.com/temporalio/sdk-dotnet/issues/507
• Ruby - https://github.com/temporalio/sdk-ruby/issues/318
• PHP - https://github.com/temporalio/sdk-php/issues/644
• Temporal CLI - N/A

Review the per-SDK tickets linked in the issue, especially Python issue 950 and pull request 1011, before choosing an implementation target. Compare which SDKs already have work underway; done requires a decided plugin model and coordinated SDK-specific support rather than an isolated change.