HDDS-7230. Implement GetKeyInfo API

[duongkame]

What changes were proposed in this pull request?

Server-side implementation of GetKeyInfo API, which implies 2 primary purposes:

1. It leverages the container location cache to avoid calling SCM to get block location information.
2. It allows S3G to call without a volume name, which the API can assume. S3G can call GetKeyInfo with assumeS3Context and OM will resolve the s3 volume context (volume name and s3 auth) and include it in the API response. This saves S3G another call to get S3VolumeContext before reading a key.

https://issues.apache.org/jira/browse/HDDS-7230

This PR only includes server-side implementation. Full client-side integration and tests will be done by HDDS-7231.

How was this patch tested?

Unit tests and standard CI: https://github.com/duongkame/ozone/actions/runs/3131964309

[duongkame]

cc. @kerneltime

[duongkame]

@adoroszlai It would be great if you can have a look.

[adoroszlai]

Thanks @duongkame for the patch, looks mostly good to me.

[kerneltime]

I can merge this in once conflicts are resolved.

[duongkame]

I can merge this in once conflicts are resolved.

Thanks for the review @kerneltime, @adoroszlai .

I've just resolved the conflicts. Let's see if there's any problem with CI workflow.

[adoroszlai]

Thanks @duongkame for the patch, @kerneltime for the review.