KAFKA-17045: Move MetadataLogConfig from kafka to kafka/raft

[ulysses-you]

The MetadataLogConfig belongs to raft, move file to raft to mach the package name.

Committer Checklist (excluded from commit message)

• Verify design and implementation
• Verify test coverage and CI build status
• Verify documentation (including upgrade notes)

[ulysses-you]

cc @jsancio @chia7712 if you have time to take a look, thank you.

[chia7712]

not sure whether it is good time to do this migration since KafkaMetadataLog is still in core module ..

[ulysses-you]

@chia7712 yeah, but the MetadataLogConfig is also in core module, which means this pr only move the file from core/src/main/scala/kafka/MetadataLogConfig.scala to core/src/main/scala/kafka/raft/MetadataLogConfig.scala.