KAFKA-18858: Refactor FeatureControlManager to avoid using uninitialized MV

[FrankYang0529]

The FeatureControlManager used MetadataVersion#LATEST_PRODUCTION
as uninitialized MV. This makes other component may get a stale MV.
In production code, the FeatureControlManager set MV when replaying
FeatureLevelRecord, so we can set Optional.empty() as uninitialized MV.
If other components get an empty result, the FeatureLevelRecord throws
an exception like FeaturesImage.

Unit test:

• FeatureControlManagerTest#testMetadataVersion: test getting MetadataVersion
  before and after replaying FeatureLevelRecord.