Core: Relocate parquet to core

[danielcweeks]

This PR relocates the parquet implementation from the iceberg-parquet project to iceberg-core so that parquet can be used as part of metadata operations.

The project and artifacts are left so that dependencies still resolve and we can deprecate in a future release.

[ajantha-bhat]

Already we have a PR and issue tracker for the same
#8500

The project and artifacts are left so that dependencies still resolve and we can deprecate in a future release.

Since, Iceberg-parquet users will definitely use Iceberg-core, I assumed that we don't have to keep dummy modules and deprecate it in future. So, I removed them directly.

[nastra]

is there anything left in iceberg-parquet or can the gradle module be removed too?

[ajantha-bhat]

@nastra: He kept dummy module for compatibility. But I think it can be removed as mentioned in #11716 (comment)

My PR has end to end work, I can revive it.
#8500

[github-actions]

This pull request has been marked as stale due to 30 days of inactivity. It will be closed in 1 week if no further activity occurs. If you think that’s incorrect or this pull request requires a review, please simply write any comment. If closed, you can revive the PR at any time and @mention a reviewer or discuss it on the dev@iceberg.apache.org list. Thank you for your contributions.

[ajantha-bhat]

Currently introducing internal writers for parquet: #11904

Once, it is merged, I will revive/rework the original #8500