* Remove all mentions of Piwik
* Kill off all consumer of the old Piwik Analytics module
* Simplify ModalManager interface
* i18n
* Attempt to fix old e2e tests
* Remove unused component
* Iterate PR
* Replace browser-encrypt-attachment with matrix-encrypt-attachment
matrix-encrypt-attachment is maintained and includes TS typings
* Upgrade matrix-encrypt-attachment to latest with default exports
when reading quicktime files for thumbnailing and/or display, clobber the mimetype from `video/quicktime` to be `video/mp4` so browsers don't choke on it.