Switch nav2_waypoint_follower to modern CMake idioms.

[clalancette]

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Basic Info

Info	Please fill out this column
Ticket(s) this addresses	Follow-up to #4357
Primary OS tested on	Ubuntu 24.04
Robotic platform tested on	N/A
Does this PR contain AI generated software?	No

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Description of contribution in a few bullet points

Change nav2_waypoint_follower to modern CMake idioms:

1. Switch from ament_target_dependencies to target_link_libraries.
2. Export a CMake target so downstream packages can use it.
3. Push the include directories down one level, which has been best practice since Humble.

Note well that this will fail to compile until cra-ros-pkg/robot_localization#895 is merged, released, and synced into Rolling.

Description of documentation updates required from your changes

None needed.

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Future work that may be required in bullet points

This is the last of the series to convert Navigation2 to modern CMake idioms. One suggestion I might make is to attempt to release the main branch of Navigation2 into Rolling to make sure we've gotten all of the dependencies correct. Short of that, this should be the end of this particular series.

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

[mergify]

@clalancette, your PR has failed to build. Please check CI outputs and resolve issues.
You may need to rebase or pull in main due to API changes (or your contribution genuinely fails).

[mergify]

@clalancette, your PR has failed to build. Please check CI outputs and resolve issues.
You may need to rebase or pull in main due to API changes (or your contribution genuinely fails).

[SteveMacenski]

Retriggering CI, is this ready to go now with binary updates?

[clalancette]

Retriggering CI, is this ready to go now with binary updates?

Yeah, I think this should be ready, though CI failed to upload coverage results.

[SteveMacenski]

That's just a rebase issue, since your branch doesn't include that file. LGTM!