refactor(elevation_map_loader)!: 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.
2. Clean unused dependencies LIST

Related links

Part of: autowarefoundation/autoware#4569

How was this PR tested?

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

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

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[esteve]

@technolojin could you also make the changes to rename the package and the directory? It's easier to review if it's all in one go. Thanks.

[codecov]

Codecov Report

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

Project coverage is 28.65%. Comparing base (b233929) to head (08d34fd).
Report is 10 commits behind head on main.

Files	Patch %	Lines
...ation_map_loader/src/elevation_map_loader_node.cpp	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #7807      +/-   ##
==========================================
- Coverage   28.66%   28.65%   -0.01%     
==========================================
  Files        1588     1589       +1     
  Lines      116375   116393      +18     
  Branches    49696    49701       +5     
==========================================
  Hits        33358    33358              
- Misses      73925    73943      +18     
  Partials     9092     9092              

Flag	Coverage Δ		*Carryforward flag
differential	0.00% <0.00%> (?)
total	28.66% <ø> (+<0.01%)	⬆️	Carriedforward from b233929

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

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[technolojin]

@technolojin could you also make the changes to rename the package and the directory? It's easier to review if it's all in one go. Thanks.

As I mentioned in autowarefoundation/autoware#4569 (comment), I will do it in separated PRs

[yukkysaito]

As I mentioned in autowarefoundation/autoware#4569 (comment), I will do it in separated PRs

I feel that splitting the PR is not particularly problematic for me.

[technolojin]

@esteve Can you response on this topic?

[esteve]

@technolojin we'll discuss this in the ASWG, because the process the perception team at TierIV is following regardin this task doesn't seem to be aligned with what we agreed originally, see https://github.com/orgs/autowarefoundation/discussions/4097#discussioncomment-9234315

As @TakaHoribe said, the Autoware project shouldn't be limited in what it can do or not just because of one company (in this case, TierIV)