[HUDI-1822] Rewriting rfc-27 for data skipping index

[nsivabalan]

What is the purpose of the pull request

• Re-writing RFC27 in the new format (moving away from wiki) with some updates to some of the design nuances.

Brief change log

(for example:)

• Modify AnnotationLocation checkstyle rule in checkstyle.xml

Verify this pull request

(Please pick either of the following options)

This pull request is a trivial rework / code cleanup without any test coverage.

(or)

This pull request is already covered by existing tests, such as (please describe tests).

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This change added tests and can be verified as follows:

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• Added integration tests for end-to-end.
• Added HoodieClientWriteTest to verify the change.
• Manually verified the change by running a job locally.

Committer checklist

• Has a corresponding JIRA in PR title & commit

• Commit message is descriptive of the change

• CI is green

• Necessary doc changes done or have another open PR

• For large changes, please consider breaking it into sub-tasks under an umbrella JIRA.

[hujincalrin]

@nsivabalan
In the RFC， key format is [ColumnId] [PartitionId] [FileId]/ [ColumnId] "agg" [PartitionId]，it will using hash32/hash128 to generate unique IDS，would like to know how to guarantee the uniqueness between two different columnNames/PartitionValues/FileNames after hash32/hash128? Cause once two different ColumnNames have the same ID after hash32, it may lead a wrong pruning results.

[nsivabalan]

@manojpec : Can you please respond to @hujincalrin 's comment above.

[hudi-bot]

CI report:

• ab3ca65 Azure: FAILURE

Bot commands

@hudi-bot supports the following commands:

• @hudi-bot run azure re-run the last Azure build

[nsivabalan]

Landing the patch for now. @manojpec plans to put up a new patch with latest updates to the RFC.