refactor(path_shifter): make member functions const as far as possible

[satoshi-ota]

Signed-off-by: satoshi-ota satoshi.ota928@gmail.com

Description

• refactor path shifter
  • fix clang-tidy warning/error
  • small logic change
  • add const

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.

[satoshi-ota]

Evaluator
This PR : 792/823
Baseline : 787/823

[codecov]

Codecov Report

Base: 10.42% // Head: 10.37% // Decreases project coverage by -0.05% ⚠️

Coverage data is based on head (5b300e5) compared to base (cf4ae72).
Patch coverage: 0.00% of modified lines in pull request are covered.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1875      +/-   ##
==========================================
- Coverage   10.42%   10.37%   -0.06%     
==========================================
  Files        1226     1226              
  Lines       87951    88386     +435     
  Branches    20463    20781     +318     
==========================================
+ Hits         9171     9172       +1     
- Misses      69276    69675     +399     
- Partials     9504     9539      +35     

Flag	Coverage Δ		*Carryforward flag
differential	1.27% <0.00%> (?)
total	10.41% <0.00%> (ø)		Carriedforward from cf4ae72

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

Impacted Files	Coverage Δ
...r_path_planner/scene_module/utils/path_shifter.hpp	0.00% <0.00%> (ø)
...er/src/scene_module/avoidance/avoidance_module.cpp	0.00% <0.00%> (ø)
.../src/scene_module/side_shift/side_shift_module.cpp	0.00% <0.00%> (ø)
...th_planner/src/scene_module/utils/path_shifter.cpp	0.00% <0.00%> (ø)
...er/src/scene_module/pull_over/pull_over_module.cpp	0.00% <0.00%> (ø)
...havior_path_planner/behavior_path_planner_node.hpp	0.00% <0.00%> (ø)
...or_path_planner/src/behavior_path_planner_node.cpp	0.32% <0.00%> (+0.10%)	⬆️

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[takayuki5168]

LGTM

[TakaHoribe]

compliment as much as possible