refactor(ekf_localizer): move header files of ekf_localizer

[Motsu-san]

Description

Headers that are not publicly exposed should be moved to src/.
This makes it clear what constitutes the public API.

Related links

Parent Issue:

• Link

How was this PR tested?

(ADDED by @sasakisasaki ) Required CI passed as this

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 50.46%. Comparing base (d091381) to head (5570e6c).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #726      +/-   ##
==========================================
+ Coverage   50.35%   50.46%   +0.10%     
==========================================
  Files         358      362       +4     
  Lines       22780    22839      +59     
  Branches    10120    10150      +30     
==========================================
+ Hits        11472    11525      +53     
- Misses      10203    10209       +6     
  Partials     1105     1105              

Flag	Coverage Δ		*Carryforward flag
daily-humble	50.69% <ø> (-0.04%)	⬇️	Carriedforward from e232aec
daily-jazzy	50.18% <ø> (-0.04%)	⬇️	Carriedforward from e232aec
differential-humble	55.38% <100.00%> (?)
total	50.38% <ø> (-0.01%)	⬇️	Carriedforward from e232aec
total-humble	50.72% <ø> (-0.01%)	⬇️	Carriedforward from e232aec
total-jazzy	50.21% <ø> (+<0.01%)	⬆️	Carriedforward from e232aec

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

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[stale]

This pull request has been automatically marked as stale because it has not had recent activity.

[Motsu-san]

Still in consideration.

[sasakisasaki]

@Motsu-san Perhaps it might be better to use include not internal as the Autoware official documentation.

[Motsu-san]

@Motsu-san Perhaps it might be better to use include not internal as the Autoware official documentation.

@sasakisasaki Thank you for your review! I'm not sure why I named as it. I'll fix it.

[sasakisasaki]

Reviewed. Also as the CI build/tests which involves whole Autoware succeeded, I agree with merging this PR. Thank you so much for your contribution!

[interimadd]

I've confirmed that all changes are for the migration of header files.
LGTM!