Convert PLUART to queue for sensor lines (#16)

[keenanjohnson]

What changed?

Implements queue-based line buffering for PLUART to prevent data loss when multiple lines arrive before being read.

How does it make Bristlemouth better?

Issue #16 raised by the devs seems to indicate a need and makes sense to me! As mentioned in the issue, many sensors issue multiple lines and this change seems to only make the project more robust to timing jitter without changing the user API.

Where should reviewers focus?

src/lib/common/payload_uart.cpp contains the important bits. I have added a set of basic unit tests as well.

Checklist

• Add or update unit tests for changed code
• Ensure all submodules up to date. If this PR relies on changes in submodules, merge those PRs first, then point this PR at/after the merge commit
• Ensure code is formatted correctly with clang-format. If there are large formatting changes, they should happen in a separate whitespace-only commit on this PR after all approvals.

[keenanjohnson]

Just ran across this project in open source and seems like a great effort! I've done a few ocean robotics projects in the past and always looking for ways to give back. I saw that this issue was open and seemed straightforward, but let me know if it's not helpful or I am headed in the wrong direction.

[towynlin]

Thanks @keenanjohnson! Please work on fixing the CI failure, and we'll help with some hardware validation.

[keenanjohnson]

Great! The latest push fixes the tests I think

[towynlin]

Hey @keenanjohnson CI is still failing — you can see the ❌ next to the latest commit and the "All checks have failed" notice at the bottom fo the PR. Here's a screenshot of the build failure:

[matt001k]

Nice, I like this change a lot!
I will give it a shot on actual hardware here soon (give me at most a week)!