refactor: improve has_many interactions + add & add another

[adrianthedev]

Description

Fixes #983

Makes the association interactions much smoother:

• when removing an associated record, we respond with a turbo stream
• same for attaching
• added "add & add another" button on the modal (enhancement on attach modal)
• we only have one turbo-frame for modals (extracted by refactor: join attach and actions modal to use the same turbo_frame #3275)
• moved some tests that require turbo requests to system tests

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works

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[Paul-Bob]

In tests, when using URLs with a turbo_frame like "/admin/resources/users/#{user.slug}/posts?turbo_frame=has_many_field_posts&view_type=table" the content is rendered inside the frame but the src is missing from the frame which results in the environment not accurately reflecting the real one..

This leads to some false positive results especially now that we use turbo_frame_reload which requires the src to reload the frame.

To properly test turbo frames in real scenarios I moved some tests from feature to system

[github-actions]

This PR has been merged into main. The functionality will be available in the next release.

Please check the release guide for more information.