Huge work; Run TxPoller in parallel

[moreal]

Warning

This pull request is too huge to review. 😭 Please read this comment as well before looking around the code. 🙏🏻

Overview

I started to work on this pull request to make handlers in TxPoller run in parallel. But this pull request becomes to include many changes:

• All handlers become an independent BackgroundService. (even for handlers in DiffPoller).
  • DiffPoller, DiffProducer and DiffConsumer has removed. Their functions are moved to BaseDiffHandler.
  • All handlers in TxPoller run in parallel, so they updates each MetadataDocument themselves.
• All initializers become an independent BackgroundService
  • Originally, Worker executed initializers but initializers will run as BackgroundService.
  • To wait until the initializers complete their job, it introduces Task IInitializerManager.WaitInitializers(CancellationToken) method. BaseDiffHandler and BaseActionHandler receives IInitializerManager instance as dependency and call it before looping its logic.
  • Also TableSheetInitializer should be run before ArenaIntializer. So ArenaInitializer receives it as dependency, and wait until TableSheetInitializer.ExecuteTask is completed.
• Diff-based handlers previously called ...Handler have been renamed to ...StateDocumentConverter.
• PlanetType became enum type.

Next step

• Configure handlers to run.
• Update Assertible to check metadata for each collection.

[Atralupus]

MTGL