Room.getAliases()

Room.getAliases() doesn't always return the canonical aliases. (tested on develop branch). This resulted in some pills not rendering correctly. I fixed that by checking this in matrix-react-sdk for pills:

```
MatrixClientPeg.get().getRooms().find((r) => {
return r.getCanonicalAlias() == resourceId || r.getAliases().includes(resourceId);
}) : MatrixClientPeg.get().getRoom(resourceId);
```

Start at the Room.getAliases() entry point and inspect how canonical aliases are collected on the develop branch. Reproduce the case where canonical aliases are missing and compare it with the matrix-react-sdk pill lookup shown in the issue; done means Room.getAliases() consistently returns the canonical aliases and the pill-rendering symptom is covered by a regression test.

Written by the indexing model from the issue text.