refactor(lane_change): update filtered objects only once

[zulfaqar-azmi-t4]

Description

calls to filterObjects are made during both before and after RTC approval.
At the same time, it is also called during stop point insertion.
As filtering objects consumes processing time, in time PR, the filterObject is done only once, and the result is assigned to a member variable in lane change module.

Related links

Parent Issue:

• Link

How was this PR tested?

PSIM.
TIER IV internal link

Notes for reviewers

None.

Interface changes

None.

Effects on system behavior

None.

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[codecov]

Codecov Report

Attention: Patch coverage is 42.85714% with 4 lines in your changes missing coverage. Please review.

Project coverage is 23.88%. Comparing base (0649ede) to head (9578c0c).
Report is 6 commits behind head on main.

Files	Patch %	Lines
...are_behavior_path_lane_change_module/src/scene.cpp	33.33%	4 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8489      +/-   ##
==========================================
+ Coverage   23.86%   23.88%   +0.01%     
==========================================
  Files        1380     1381       +1     
  Lines      101866   101896      +30     
  Branches    38792    38797       +5     
==========================================
+ Hits        24308    24335      +27     
- Misses      75047    75129      +82     
+ Partials     2511     2432      -79     

Flag	Coverage Δ		*Carryforward flag
differential	15.51% <42.85%> (?)
total	23.87% <ø> (+<0.01%)	⬆️	Carriedforward from a612530

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