Use default initializers in collision_common.h

[marioprats]

Description

Updates structs in collision_common.h to use default initialization, instead of constructors.
This should be less error-prone and safer, since it ensures all atomic types have been initialized, but it also enables designated initialization, e.g.:

collision_detection::CollisionRequest request{ .contacts = true };

Checklist

• Required by CI: Code is auto formatted using clang-format
• Extend the tutorials / documentation reference
• Document API changes relevant to the user in the MIGRATION.md notes
• Create tests, which fail without this PR reference
• Include a screenshot if changing a GUI
• While waiting for someone to review your request, please help review another open pull request to support the maintainers

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (26a8937) 50.35% compared to head (d56c1d0) 50.31%.
Report is 1 commits behind head on main.

❗ Current head d56c1d0 differs from pull request most recent head b6c975a. Consider uploading reports for the commit b6c975a to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #2475      +/-   ##
==========================================
- Coverage   50.35%   50.31%   -0.03%     
==========================================
  Files         390      390              
  Lines       31954    31937      -17     
==========================================
- Hits        16087    16066      -21     
- Misses      15867    15871       +4     

Files	Coverage Δ
...lude/moveit/collision_detection/collision_common.h	74.42% <ø> (-9.45%)	⬇️

... and 5 files with indirect coverage changes

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