test(lane_departure_checker): add unit test for createVehiclePassingAreas

[kyoichi-sugahara]

Description

add unit test for createVehiclePassingAreas

How was this PR tested?

confirmed test result was all passed.

1: [==========] Running 26 tests from 7 test suites.
1: [----------] Global test environment set-up.
1: [----------] 4 tests from CreateVehiclePassingAreasTest
1: [ RUN      ] CreateVehiclePassingAreasTest.ReturnsEmptyAreaForEmptyInput
1: [       OK ] CreateVehiclePassingAreasTest.ReturnsEmptyAreaForEmptyInput (0 ms)
1: [ RUN      ] CreateVehiclePassingAreasTest.ReturnsSameAreaForSingleFootprint
1: [       OK ] CreateVehiclePassingAreasTest.ReturnsSameAreaForSingleFootprint (0 ms)
1: [ RUN      ] CreateVehiclePassingAreasTest.CreatesValidHullForAdjacentFootprints
1: [       OK ] CreateVehiclePassingAreasTest.CreatesValidHullForAdjacentFootprints (0 ms)
1: [ RUN      ] CreateVehiclePassingAreasTest.HandlesNonAdjacentFootprints
1: [       OK ] CreateVehiclePassingAreasTest.HandlesNonAdjacentFootprints (0 ms)
1: [----------] 4 tests from CreateVehiclePassingAreasTest (0 ms total)

Notes for reviewers

This PR includes refactor PR so please check together with the PR.

Interface changes

None.

Effects on system behavior

None.

[github-actions]

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[zulfaqar-azmi-t4]

Is it supposed to be i < footprint.size() - 1 or i < footprint.size()?
If footprint.size() == 0, then we might have an overflow.