Introducing stylelint with configuration rules compliant to
Wikimedia CSS Coding Standards 'stylelint-config-wikimedia', nullifying
some for now and making majority pass.
Change-Id: I2c4acee41c9b56d9b00e2a2c5b7ab0ab5de454ce
Mainly used for mobile actions, and should be appended to the
overlay - this widget assumes it should appear and then fade out
with some confirmation message.
Also moved 'doubleCheck' icon to the ooui definitions, including
an inverted icon that is necessary for this widget.
Bug: T141404
Change-Id: I67a44962eaee6b7bd8cac26dcb5277177fa5d224