datasource :Fix panic in transaction subsystem

[puerco]

Summary

This commit fixes a panic in the data source transaction subsystem when options are nil.

Fixes: #5113

Change Type

Mark the type of change your PR introduces:

• Bug fix (resolves an issue without affecting existing features)
• Feature (adds new functionality without breaking changes)
• Breaking change (may impact existing functionalities or require documentation updates)
• Documentation (updates or additions to documentation)
• Refactoring or test improvements (no bug fixes or new functionality)

Testing

This pr modifies the beginTx() in the transaction logic of the data sources to initialize an options set if none is passed. We also make sure that the read-only methods (list/get) retrieve initialize their transactions as read only.

Review Checklist:

• Reviewed my own code for quality and clarity.
• Added comments to complex or tricky code sections.
• Updated any affected documentation.
• Included tests that validate the fix or feature.
• Checked that related changes are merged.

[coveralls]

coverage: 55.222% (-0.009%) from 55.231%
when pulling 41792ca on puerco:fix-datasources-panic
into 5dfc7d0 on mindersec:main.