Tracked by: #41 and #10

After some discussion on two alternatives on how to tackle an error path with vote extensions in v0.38.x, the CometBFT decided to remove the possibility for blocksync to be configurable (it must always be active).

Therefore:

• In v0.37.x we need to deprecate the CometBFT configuration options that allows the operator to disable blocksync config: mark block_sync key as deprecated #414
• In v0.38.x these options will be removed, as part of vote extension implementation config: remove block_sync key #415

DoD

• There is an (early) release of v0.37.x that warns the operator with a deprecation message if they configure their node to disable blocksync
• It is not possible for the operator to disable blocksync in v0.38.x