Update obstacle layer usage of max ranges

[sd-kudan]

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#5476
Primary OS tested on	Ubuntu
Robotic platform tested on	gazebo simulation
Does this PR contain AI generated software?	No
Was this PR description generated by AI software?	No

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Description of contribution in a few bullet points

To address issue reported in #5476 of obstacles being cleared when reversing away from them, the following changes are made:

• When marking obstacles from new observations, the check against obstacle_max_range is done in grid cell space for consistency with the ray tracing free space check against raytrace_max_range
• When ray tracing, excluded the cell containing the observation point so that an obstacle is not cleared if it is present in the current measurement but raytrace_max_range > obstacle_max_range

Description of documentation updates required from your changes

Description of how this change was tested

• Unit tests added for obstacle layer marking and clearing
• Tested in gazebo simulation

Demo

Before:

obstacle_layer_clearing.mp4

After:

obstacle_layer.mp4

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Future work that may be required in bullet points

For Maintainers:

• Check that any new parameters added are updated in docs.nav2.org
• Check that any significant change is added to the migration guide
• Check that any new features OR changes to existing behaviors are reflected in the tuning guide
• Check that any new functions have Doxygen added
• Check that any new features have test coverage
• Check that any new plugins is added to the plugins page
• If BT Node, Additionally: add to BT's XML index of nodes for groot, BT package's readme table, and BT library lists
• Should this be backported to current distributions? If so, tag with backport-*.

[mergify]

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