Add a parameter to set initial enabled state for the collision monitor

[armgits]

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#5493
Primary OS tested on	Ubuntu
Robotic platform tested on	Turtlebot 3 Loopback 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

• Added a parameter to set the initial state for for the collision monitor to start in enabled/disabled state.

Description of documentation updates required from your changes

• Need to add this parameter to the collision monitor node documentation

Description of how this change was tested

• This change was tested in the TB3 Loopback simulation to check if it actually works. I kept an eye on the console log to see if the correct message was printed during node configuration. I also tried modifying the parameter in the parameters file within the bring up package to see if the changes were applied correctly.

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Future work that may be required in bullet points

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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-*.

[codecov]

Codecov Report

�� All modified and coverable lines are covered by tests.

Files with missing lines	Coverage Δ
...2_collision_monitor/src/collision_monitor_node.cpp	97.23% <100.00%> (+0.04%)	⬆️

... and 6 files with indirect coverage changes

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[SteveMacenski]

@armgits please open a docs PR to add this to the configuration guide for the monitor. Then I can merge the pair once CI passes

[armgits]

On it!