Show canonical alias in URL bar

[dbkr]

Use matrix-org/matrix-js-sdk#140 to get the canonical alias, because that's a thing now.

[richvdh]

Hrm.

1. should we fall back to a (semi-random) m.room.aliases alias if there is no canonical_alias in the room?
2. Should we get rid of MatrixTools.getCanonicalAliasForRoom? (or update it in light of point 1 and continue to use it)?

[dbkr]

Oh, yes - I was actually going to get rid of all of MatrixTools as the only other use is getting a room from an alias somewhere else, which is also wrong. This should still delete this from the file though.

[dbkr]

ptal