refactor(goal_planner): divide sort function

[soblin]

Description

divide pull over path candidates sort functionality to a utility function.

Related links

Parent Issue:

• https://tier4.atlassian.net/browse/RT1-8337

How was this PR tested?

• https://evaluation.tier4.jp/evaluation/reports/c158543d-cfbc-589a-9b97-234fd80ed4f4?project_id=prd_jt
• https://evaluation.tier4.jp/evaluation/reports/372080f8-e1f2-5dca-a6af-0b2a90e1e2e0?project_id=prd_jt

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

[github-actions]

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[codecov]

Codecov Report

Attention: Patch coverage is 0% with 37 lines in your changes missing coverage. Please review.

Project coverage is 29.80%. Comparing base (5ced41e) to head (81d7e3d).
Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
...th_goal_planner_module/src/goal_planner_module.cpp	0.00%	37 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #9650      +/-   ##
==========================================
- Coverage   29.82%   29.80%   -0.02%     
==========================================
  Files        1443     1448       +5     
  Lines      108539   108609      +70     
  Branches    42581    42583       +2     
==========================================
  Hits        32376    32376              
- Misses      72983    73053      +70     
  Partials     3180     3180              

Flag	Coverage Δ		*Carryforward flag
differential	0.52% <0.00%> (?)
total	29.83% <ø> (+<0.01%)	⬆️	Carriedforward from 5ced41e

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