Currently MinervaNeue doesn't provide a visual focus feedback to keyboard/assistive technology users.
This is an accessibility anti-pattern as described in http://www.outlinenone.com/
{F28376909}
It also isn't relying on mediawiki.ui-input (any more?), so let's rebuild the focus styles according to #ui-standardization component treatment to resolve the focus issue.
== Expected result
{F28377161}
[X] No visual change in default appearance
[X] Add standard focus treatment
Additionally let's care for
[X] cleaning up CSS a bit (removing old Nokia60 override, bring properties in order etc.)
[] remove the focus flash (https://phabricator.wikimedia.org/T218154#5079887)
= Developer note
Request from @Volker_E is to review [[ https://gerrit.wikimedia.org/r/#/c/mediawiki/skins/MinervaNeue/+/496059/1/resources/skins.minerva.base.styles/ui.less | this patch ]]