fix(positioner_box): remove CompactPopupWidget inheritance

[wyzula-jan]

Description

CompactPopup inheritance was messing up layout of the widget. Since the CompactPopupWidget is not used in any production, we can get rid of it for now.

Needed for #1105

[Copilot]

Pull request overview

This PR removes CompactPopupWidget inheritance from the PositionerBox widget hierarchy to resolve layout issues, and updates dependent widgets/tests accordingly. This supports follow-up work needed for #1105.

Changes:

• Drop CompactPopupWidget from PositionerBoxBase and replace the previous container/layout plumbing with an explicit main_layout.
• Update PositionerBox, PositionerBox2D, and PositionerGroupBox to stop using compact-popup-specific APIs/signals.
• Adjust PositionerControlLine UI/layout behavior and update unit tests to reflect new module paths and sizing expectations.

Reviewed changes

Copilot reviewed 9 out of 9 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
tests/unit_tests/test_positioner_box_2d.py	Updates patch targets to the new positioner_box_base module path.
tests/unit_tests/test_positioner_box.py	Updates patch targets and relaxes/aligns height assertions with the new layout behavior.
bec_widgets/widgets/control/device_control/positioner_group/positioner_group.py	Removes compact-popup configuration and expand handling now that the base no longer supports it.
bec_widgets/widgets/control/device_control/positioner_box/positioner_control_line/positioner_control_line.ui	Updates size policies/margins to better support the one-line layout.
bec_widgets/widgets/control/device_control/positioner_box/positioner_control_line/positioner_control_line.py	Adds responsive layout/orientation logic for the indicator and fixed-height line behavior.
bec_widgets/widgets/control/device_control/positioner_box/positioner_box_base.py	Removes CompactPopupWidget inheritance and introduces an explicit main_layout.
bec_widgets/widgets/control/device_control/positioner_box/positioner_box_2d/positioner_box_2d.py	Switches to main_layout and removes compact-popup label usage.
bec_widgets/widgets/control/device_control/positioner_box/positioner_box/positioner_box.py	Switches to main_layout and removes compact-popup label initialization.
bec_widgets/widgets/control/device_control/positioner_box/_base/init.py	Removes the deprecated _base package export.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[codecov]

Codecov Report

❌ Patch coverage is 78.66667% with 16 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
...positioner_control_line/positioner_control_line.py	71.92%	14 Missing and 2 partials ⚠️

📢 Thoughts on this report? Let us know!