[server] Support generating rack aware bucket assignment when creating table

[swuferhong]

Purpose

Linked issue: close #785

Currently, Fluss only support generate bucket assignment info using round-robin strategy. However, in some cases, like deploy on K8s, we need to avoid multi replicas of one bucket was deployed to same host.
So, in this pr I will introduce one rack aware bucket assignment strategy. For example:

If we have a tabletServer set as follow:
ts-id -> machine rack
0 -> "rack1"
1 -> "rack3"
2 -> "rack3"
3 -> "rack2"
4 -> "rack2"
5 -> "rack1"

First we will create a rack alternated tabletServers list:

[0, 3, 1, 5, 4, 2]

the list is in order rack1 -> rack2 -> rack3 -> rack1 -> rack2 -> rack3, and the preview tabletServerId lower than the next tabletServerId for the same rack.

Then an easy round-robin assignment can be applied. Assume 6 buckets with replica factor of 3, the assignment will be:

bucket0 -> 0,3,1
bucket1 -> 3,1,5
bucket2 -> 1,5,4
bucket3 -> 5,4,2
bucket4 -> 4,2,0
bucket5 -> 2,0,3

Once it has completed the first round-robin, if there are more buckets to assign, the algorithm will start shifting the followers. This is to ensure we will not always get the same set of sequences. In this case, if there is another bucket to assign (bucket6, bucket7), the assignment will be:

bucket6 -> 0,4,2 (instead of repeating 0,3,1 as bucket0)
bucket7 -> 3,2,0 (instead of repeating 3,1,5 as bucket1)

Brief change log

Tests

API and Format

Documentation

[swuferhong]

@wuchong @luoyuxia @loserwang1024 , the pr to support generating rack aware bucket assignment, PTAL, thx.

[loserwang1024]

. In this case, if there is another bucket to assign (bucket6, bucket7), the assignment will be:
bucket6 -> 0,4,2 (instead of repeating 0,3,1 as bucket0)
bucket7 -> 3,2,0 (instead of repeating 3,1,5 as bucket1)

8 bucket( * 3) to 8 servers:

• server 0: 5 buckets
• server 1: 5 buckets
• server 2: 4 buckets
• server 3: 4 buckets
• server 4: 3 buckets
• server 5: 3 bucket

8 bucket( * 3) to 3 racks:

• rack 1 (server 0 & 5): 8 bucket
• rack 2 (server 3 & 4): 7 bucket
• rack 3( server 1 & 2): 9 bucket

It seems not even enough for servers and racks?