Fix logo in nav2 panel

[ajtudela]

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses
Primary OS tested on	Ubuntu 22.04
Robotic platform tested on	None
Does this PR contain AI generated software?	No

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Description of contribution in a few bullet points

I noticed that the only way to see the logo in the nav2 panel was to run Rviz from a src folder with this structure: src/navigation2. With this fix, the logo is found by loading its resource like any other Rviz plugin.

Description of documentation updates required from your changes

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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

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark: