Added cast to float to getClosestAngularBin return for behavior consistency

[hsong-MLE]

---

Basic Info

Info	Please fill out this column
Ticket(s) this addresses	#4094
Primary OS tested on	Ubuntu
Robotic platform tested on	N/A
Does this PR contain AI generated software?	No

---

Description of contribution in a few bullet points

• This small fix improves the behavioral consistency of the NodeHybrid::getClosestAngularBin method.
• Unit tests of the method are added.

Description of documentation updates required from your changes

• N/A

---

Future work that may be required in bullet points

• N/A

For Maintainers:

• Check that any new parameters added are updated in navigation.ros.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

[SteveMacenski]

@hsong-MLE you have commits in this PR that are not part of your work. Normally I wouldn't split hairs, but those commits cannot be backported to Humble, so I need you to remove them so this can be put in Humble as well for you.

Clone main -> fetch origin -> checkout a new branch -> cherry pick just your commit -> push & open PR