Refactor controller

[eborghi10]

This PR is a huge refactor of the code previous to adding Vision MPC capabilities. The main idea of this change is to modify the code so it better matches the original MIT Controller but with some other cool features:

• Added some missing third-party libraries (Goldfarb Optimizer, ParamHandler & inih)
• Added config files (user & control parameters) to customize the control of the robot at launch time with YAML files
• Added vision launch argument to ROS

TODO:

• Robot not moving after receiving velocity commands
• Robot is not completely standing still in the STAND gait
• Enable roslint
• Add documentation to YAML parameters
• Clean up README file