No prefix for FSM commands

[plasorak]

This PR fixes the fsm command prefix saga. Description on Monday morning.

[plasorak]

Here is a description of the changes in this PR:

• the describe_fsm endpoint is a bit more complicated. It now accepts a PlainText argument that can be
  • None: in that case, the function returns a list of descriptions for the transitions accessible in the current state of the controller
  • a state name: the function returns a list of descriptions for the transitions accessible from the state that was requested in its input
  • a transition name: the function returns the description for the transition requested in its input
  • all-transitions: the function returns the descritions of all the transitions (accessible right now and not)
• This upgraded describe_fsm is used by the controller-shell to build shell commands in the main of the shell (i.e. when the shell first connects to the controller).
• For the unified-shell it's a bit more complicated, the controller doesn't exist so the describe_fsm endpoint doesn't exist, and the configuration isn't entirely specified. To achieve the same behaviour, the following was done:
  • The path of the configuration isn't passed in boot anymore, but to the shell, this means user would now have to execute drunc-unified-shell ssh-standalone path/to/config.data.xml session-name.
  • We then create a temporary StatefulNode object, and call the underlying function used by describe_fsm to generate the shell commands.

For users, this means:

• No need to specify the prefix fsm before sending a transition to the controller
• Batch command now work (for example I can do drunc-unified-shell ssh-standalone data.xml session-name conf start --disable-data-storage 123 enable-trigger)
• The unified shell command line argument changes from being drunc-unified-shell ssh-standalone to drunc-unified-shell ssh-standalone data.xml session-name, and boot takes no arguments anymore.

[PawelPlesniak]

For the last BP, this is drunc-unified-shell ssh-standalone test/config/test-session.data.xml test-session and not drunc-unified-shell ssh-standalone data.xml test-session