Feature: Query Loop Block Support

[s3rgiosan]

Warning

This PR is based on #97

Description of the Change

This PR introduces Content Connect relationship support for the Query Loop block, allowing posts to be filtered based on relationships.

Closes #83

How to test the Change

Changelog Entry

Added - Query Loop block integration with Content Connect relationships.

Credits

Props @s3rgiosan

Checklist:

• I agree to follow this project's Code of Conduct.
• I have updated the documentation accordingly.
• I have added Critical Flows, Test Cases, and/or End-to-End Tests to cover my change.
• All new and existing tests pass.

[s3rgiosan]

I've created a try/block-editor-ui all-in-one branch to make it easier to test the features in both the block and classic editors, as well as the Query Loop integration.

[jeffpaul]

@rickalee @fabiankaegy bumping this for your review

[benlk]

Note that we'll also need a button to clear search query parameters: either just this integration's parameters, or all query parameters currently in use.

[s3rgiosan]

Note that we'll also need a button to clear search query parameters: either just this integration's parameters, or all query parameters currently in use.

@benlk Clearing all query parameters is tricky. The Query block’s core filters don’t offer direct integration, and plugins like Advanced Query Loop can extend or alter them. That makes it hard to identify which filters are active or what the default state should be. I’ve switched from PanelBody to ToolPanel in the UI, which makes it easier to reset custom parameters tied to this integration.