Use Platformio lib_deps instead of manually downloading libraries where possible

[gautamdayal]

At the moment, our lib folder is full of libraries that are manually added. Though this works, we might as well use the library dependencies functionality that PlatformIO provides. Some minor changes may have been made to some libraries (lke radiohead for telemetry) so those can be left alone.

As of now, the only library we import through pio is pwmservo, we should start doing the same for others.