Add a new goal to distribute topic leaders fairly

[hmit]

Summary

1. Why: In current CC goals, there is no goal to balance a topic leaders only which ensure a fair distribution of load for not log compacted topics. The rebalance looks at historic loads for replica placement and it's possible that load changes temporarily causing load-skew for brokers. A potential solution to this problem is to distribute topic leader partitions fairly across all the brokers.
2. What: Add a new Topic Replica Leader distribution goal.

This PR adds a new goal to distribute Leaders Replica for every topic in a fair manner across all the brokers. If the partition count is not a multiple of brokers, some brokers do end up with extra partitions.

The thresholds can be configured using 3 new knobs added to AnalyzerConfig.

The new goal is modeled after existing TopicReplicaDistributionGoal with following differences:

1. This is a hard goal
2. It looks at leader replicas in a broker only
3. For candidate brokers with equal number of leader replicas for a topic, it uses total leader replicas as a tie-break

Categorization

• documentation
• bugfix
• new feature
• refactor
• security/CVE
• other