[cli] New outdated command

[Brianzchen]

Closes #2077. User can run flow-typed outdated to render a cli table letting the user know which deps are outdated.

• Either the lib def was a stub but is now typed
• Or it was typed but there's been a change checking whether the libdef signature has changed

Notes on extra changes:

• Added test:watch script to easily tweak changes
• determineFlowVersion renamed to determineFlowSpecificVersion to avoid name conflict and shift to lib for reuse with outdated command

[AndrewSouthpaw]

Seems pretty useful! What else needs to be done for this to not be a WIP?

[Brianzchen]

Seems pretty useful! What else needs to be done for this to not be a WIP?

The comment blocks if you read the command basically outlines all the places I still haven't figured out yet. It's definitely a fun change imo but I've just been preoccupied with other stuff. Given the complexity vs the value I've just put a much lower priority on this so far.

Also it'll need tests which shouldn't be too difficult once the change is done.

[Brianzchen]

Only have tests remaining!