Add a controller for drones

[YifeiNie]

Adapted to GenesisPlayground, path is src/env/gs_env/sim/controllers.
Problems shown in Genesis main repo is caused by my version management issues, and this PR has no need to fix.
For details, see #1602

[YilingQiao]

is this uploaded by mistake?

[YifeiNie]

No, the controller contains 3 types: angle controller, angle rate controller and position controller.
The first two controller support inputs as follows: a remote controller (RC), custom command (action), or both.
betaflight_4.4.0_STM32H743_forRC.hex is a modified executable program (firmware) for specific embeded device (also named flight controller) which is usually used in a real drone:
The firmware is modified from BetaFlight, a project widely used for FPV.

Users can simply flash the modified firmware onto their flight controller, connect the RC, plug the UART port into a computer, and then launch the drone controller in Genesis. After that, they can control the drone using the RC. For more detailed operations, see src/env/gs_env/sim/controllers/drone_controller/README.md in this PR and examples/drone/controller/README.md

It should be noted that "use RC to control a drone" is an interactive demo, remove it will not affect the main function of this PR, but there will be a lack of an interactive and fast verification method.

[yun-long]

Thank you for your contribution. It will merge it to the drone branch since the code still needs some significant refactorizations to meet the requirements of the main branch.