refactor(shape_estimation)!: fix namespace and directory structure

[technolojin]

Description

This PR puts headers in the autoware namespace.

Additional works

1. Align directory structure to follow the coding guidelines.

Related links

Part of: autowarefoundation/autoware#4569

How was this PR tested?

Tested in a local recompute environment and the TIER IV Cloud environment.

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

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[codecov]

Codecov Report

Attention: Patch coverage is 9.67742% with 56 lines in your changes missing coverage. Please review.

Project coverage is 28.64%. Comparing base (99c7c57) to head (23d7434).
Report is 32 commits behind head on main.

Files	Patch %	Lines
...tection_by_tracker/src/tracker/tracker_handler.cpp	0.00%	31 Missing ⚠️
...erception/shape_estimation/lib/shape_estimator.cpp	20.00%	12 Missing ⚠️
...erception/detection_by_tracker/src/utils/utils.hpp	0.00%	5 Missing ⚠️
...ction_by_tracker/src/detection_by_tracker_node.cpp	0.00%	3 Missing ⚠️
...tection_by_tracker/src/tracker/tracker_handler.hpp	0.00%	2 Missing ⚠️
...toware/shape_estimation/corrector/no_corrector.hpp	0.00%	1 Missing ⚠️
...ude/autoware/shape_estimation/filter/no_filter.hpp	0.00%	1 Missing ⚠️
...ion/shape_estimation/src/shape_estimation_node.cpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7844      +/-   ##
==========================================
- Coverage   28.65%   28.64%   -0.02%     
==========================================
  Files        1587     1608      +21     
  Lines      116361   116474     +113     
  Branches    49700    49718      +18     
==========================================
+ Hits        33345    33359      +14     
- Misses      74014    74110      +96     
- Partials     9002     9005       +3     

Flag	Coverage Δ		*Carryforward flag
differential	2.99% <9.67%> (?)
total	28.66% <ø> (+<0.01%)	⬆️	Carriedforward from 471c870

*This pull request uses carry forward flags. Click here to find out more.

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[yukkysaito]

LGTM

[yukkysaito]

It seems that shape_estimator.hpp needs to be made public for other packages, but many of the other .hpp files don't seem to need to be public. As a first step, it might be a good idea to merge everything first and then move the .hpp files that don't need to be public afterwards.

[technolojin]

I know that other than shape_estimator.hpp is closed within the package.
Directory structure may need to be aligned and fixed later.

[YoshiRi]

LGTM with a trivial comment