'Path' type for commands lib Arguments

[whyrusleeping]

I've wanted a PathArg type for the commands libs that will validate that the content its passed is a valid ipfs path, and allow typed access to that to the consumers of the cmds.Request

[whyrusleeping]

This would help prevent problems like #2715

[Kubuxu]

valid ipfs path means resolve it locally?

[whyrusleeping]

Not resolve locally, but call path.ParsePath on it.

[Kubuxu]

Making the check during parsing should be easy. Typed access would be harder and will require changes in most commands definitions.

[whyrusleeping]

Nah, i'm thinking that we add a req.Paths() accessor or something to the request object. This would require changing a lot of command definitions, but would also clean them up dramatically

[djdv]

Is this pull relevant? #1740