Issue #417: Abstract the Qbeast Snapshot Module

[JosepSampe]

Description

This is a small initial part of issue #398.

The aim of this PR is to allow the DeltaQbeastSnapshot to accept the tableID as an input parameter instead of a Delta snapshot. This will make the top-level QbeastSnapshot class more abstract and enable better integration with other table formats.

Related tests have also been adapted to remove the strict dependency on org.apache.spark.sql.delta.DeltaLog. In the future, the tests will instantiate a QbeastSnapshot instead of a DeltaQbeastSnapshot to make them more generic.

Type of change

Refactoring

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).

[cugni]

Just a few comments. I like that this PR also solve another issue, when we were reloading the deltaLog multiple times in the IndexTables, instead of only once for each QbeastStapshot

[osopardo1]

Before merging and approving the PR, I would ask to add an issue with the scope and link the specific number instead of #398 🙏

Also, some other comments to be resolved: