The bulk of this is just export/import changes, though there's a couple pieces to highlight:
* We no longer use default exports. This is because it's discouraged by the JS community, though not in any official capacity.
* We now use `polyfillSuper` for some prototype inheritance because the tests, and sometimes webpack, break on "cannot call EncryptionAlgorithm without 'new'". It's very much a workaround, and definitely not needed when we use real classes.
There is some import shuffling to help keep the imports clean - this was done by my IDE.
Issue described in: https://github.com/vector-im/riot-web/issues/9690
matrix-react-sdk was patched separately, so that it won't call `mxcUrlToHttp()`
(and in turn `getHttpUriForMxc()`) with non-integer sizes.
This patch fixes the JS SDK as well, hoping to prevent the same issue
from happening on other clients (besides matrix-react-sdk / riot-web).
Signed-off-by: Slavi Pantaleev <slavi@devture.com>
