* Add intercept of `config.json`
To help make sure that we run our tests against a known config, rather than
accidentally making requests to `matrix.org`.
* Remove now-redundant stubs of matrix.org files
Now that we intercept config.json, all this stuff is redundant.
* Reinstate fixture which is actually used
Turns out this is used after all
* Add a `map_style_url`
* disable failing axe check
* Spike AXE A11Y testing in Cypress
* Fix NewRoomIntro breaking html/aria list rules
* Fix HeaderButtons breaking aria role semantics rules
* missing type
* Switch left panel from aside to nav and include space panel
* Give the page a main heading of the room name when viewing a room
* Use header landmark on RoomHeader
* Improve aria attributes on composer when autocomplete is closed
* Fix aria-owns on RoomHeader
* Give Spinner an aria role
* Give server picker help button an aria label
* Improve auth aria attributes and semantics
* Improve heading semantics in use case selection screen
* Fix autocomplete attribute to be valid
* Fix heading semantics on login page
* Improve Cypress axe testing
* Add axe tests
* Stop synapse after the timeline tests
* Await spinners to fade before percy snapshotting timeline tests
* Improve naming of plugin
* Update snapshots
* Fix accidental heading change
* Fix double synapse stoppage
* Fix Cypress timeline avatar assertions to be DPI agnostic
* Fix aria attributes on date separators
* delint
* Update snapshots
* Revert style change
* Skip redundant call
Richard van der Hoff