Fix clang-tidy in CI, add further documentation

[henrygerardmoore]

This fixes clang-tidy by setting the C++ std (since the default on ubuntu 20.04 is not C++ 17).

Additionally, I add the skeleton of lots of docs.

Finally, this adds a proper docs page for the transform sensor.

Reviewing instructions

Mostly just see that CI is ✔️ and read through transform_sensor.md for content and clarity. The docs skeleton is just there to make adding them easier and more standardized, so as to encourage it. The changes to unicycle_2d_ignition were just to make clang-tidy have a cpp file to run on (since at the moment it'll only run on changed cpp/hpp files).

[marioprats]

Looks good!
Q: can the transform sensor be used to estimate the odometry of a body, when that body is moving and the AR tags are fixed?
I'm thinking that's probably a more common example, e.g. fixed AR tags on walls and a robot moving and estimating motion based on those AR tags.

[henrygerardmoore]

Looks good! Q: can the transform sensor be used to estimate the odometry of a body, when that body is moving and the AR tags are fixed? I'm thinking that's probably a more common example, e.g. fixed AR tags on walls and a robot moving and estimating motion based on those AR tags.

I don't think so without modifications. This would require knowing the transform from the current estimation frame to the robot CoM, which we currently don't have a way to get. To modify this sensor to be able to do that, though, wouldn't be too hard at all.

[henrygerardmoore]

Just pushed a change that will make clang-tidy fail but applies the new clang-format to everything. I'm going to leave clang-tidy failing because I want to fix things incrementally instead of all at once, but the clang-format changes make it run on all the cpp and hpp files.