Refactor CLI submodule

Move command parsing to doCommand
Parse command with splitString instead of stringToken
Trim commands
Move cliTestMotor to the bottom
Rename parseInput to handleInput, which is more clear
Move motor test function to motors.ino

gazebo/flix.h

@@ -34,8 +34,8 @@ void controlTorque();
 void showTable();
 void sendMotors();
 bool motorsActive();
+void doCommand(String str);
 void cliTestMotor(uint8_t n);
-String stringToken(char* str, const char* delim);
 void normalizeRC();
 void printRCCal();
 void processMavlink();