Create functional indexes on multiple columns with a single create index command

Right now, user can just create one partition with a create index command (or using async indexer). So, the code assumes that the user is not creating multiple functional indexes in the same job but we can extend the functionality.

[https://github.com/apache/hudi/pull/9872#discussion_r1377110843]

[https://github.com/apache/hudi/pull/9872#discussion_r1377090656]

## JIRA info

- Link: https://issues.apache.org/jira/browse/HUDI-7026
- Type: Task
- Epic: https://issues.apache.org/jira/browse/HUDI-512
- Fix version(s):
- 1.1.0

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## Comments

24/Jul/24 07:12;codope;Punting this for 1.1.0. We need to enahance the sql grammar to support this.;;;