Command prompt access to msigs

[aaroncox]

The msigs themselves aren't functional until #244 is completed, but we should add a new pattern for the search box that allows navigating to msigs.

Maybe it's a search pattern where if you enter:

[account]/[proposal]

Into the box, it auto completes to an msig?

So if a user were to type:

jesta.x/testmsig2

It would resolve to and suggest:

/en/eos/msig/jesta.x/testmsig2