refactor(radar_tracks_msgs_converter)!: fix namespace and directory structure

[technolojin]

Description

This PR puts headers in the autoware namespace.
Part of: autowarefoundation/autoware#4569

Additional works

1. Align directory structure to follow the coding guidelines.
2. Clean unused dependencies list

Tests performed

Not applicable.

Effects on system behavior

Not applicable.

Interface changes

Not applicable.

Pre-review checklist for the PR author

The PR author must check the checkboxes below when creating the PR.

• I've confirmed the contribution guidelines.
• The PR follows the pull request guidelines.

In-review checklist for the PR reviewers

The PR reviewers must check the checkboxes below before approval.

• The PR follows the pull request guidelines.

Post-review checklist for the PR author

The PR author must check the checkboxes below before merging.

• There are no open discussions or they are tracked via tickets.

After all checkboxes are checked, anyone who has write access can merge the PR.

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 0.00%. Comparing base (507e3f4) to head (1b626a5).
Report is 145 commits behind head on main.

Files	Patch %	Lines
...converter/src/radar_tracks_msgs_converter_node.cpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #7653       +/-   ##
==========================================
- Coverage   14.84%   0.00%   -14.85%     
==========================================
  Files        1999      34     -1965     
  Lines      139163    1916   -137247     
  Branches    43716      78    -43638     
==========================================
- Hits        20661       0    -20661     
+ Misses      95731    1916    -93815     
+ Partials    22771       0    -22771     

Flag	Coverage Δ
differential	0.00% <0.00%> (?)
total	?

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[github-actions]

Thank you for contributing to the Autoware project!

🚧 If your pull request is in progress, switch it to draft mode.

Please ensure:

• You've checked our contribution guidelines.
• Your PR follows our pull request guidelines.
• All required CI checks pass before marking the PR ready for review.

[scepter914]

LGTM
(Note: without checking acting, after integrating with other PRs and checking acting this PR can be merged)