Issue #459: Deprecate StringHistogram for backward compatibility

[osopardo1]

Description

Fixes #459

Type of change

Bug Fix to ensure backward compatibility within new versions.

Checklist:

Here is the list of things you should do before submitting this pull request:

• New feature / bug fix has been committed following the Contribution guide.
• Add logging to the code following the Contribution guide.
• Add comments to the code (make it easier for the community!).
• Change the documentation.
• Add tests.
• Your branch is updated to the main branch (dependent changes have been merged).

How Has This Been Tested? (Optional)

This will be tested with an old table written with histogram transformation and version 0.7.0 of Qbeast Spark.

[osopardo1]

After discussion, we agreed on:

• Allow writing with StringHistogramTransformer and StringHistogramTransformation.
• Use superseded and merge methods to change between StringHIstogram and CDF for the moment.
• Add a method to change from histogram to cdf metadata.

I would update the PR in the upcoming days.

[osopardo1]

I would merge with main and then we can proceed to the squash 🐒

[Jiaweihu08]

Good job!