Feature/quickster footstep provider

[stefanfasano]

This is the initial groundwork for the implementation of Quickster's footstep calculator into the regular walking controller via the CSG (in step generator thread).

Tests included in this PR:

• QFPTest; this tests switching between CSG modes while walking in place and standing in place

The major ongoing issues include:

• Horrible walking speed tracking, due to horrible swing foot touchdown tracking

The next steps include:

• Solving the above bug
• New message type to ensure things on the controller side know which CSG mode is in use
• Implementation into whole body MPC scheme
• Hardware testing on robot
• Max speed limits along with