As of v.0.26.0 'settings' and 'advanced' icon are confusingly named to OOUI developers and with the new icon set also signify slightly different use case.
We should rename it to 'pageSettings' and 'settings'. Related: T190175
Due to naming conflict, we'll have to do it in sequences:
[x] Rename filenames used for 'settings'
[x] Add 'pageSettings'
[x] and add 'settings' to same icon packs
[x] [[ https://codesearch.wmflabs.org/search/?q=%3A%20%27settings%27&i=nope&files=&repos= | Replace usage of 'settings' with 'pageSettings' ]]
[x] ~~OOUI toolbar~~ 'settings' here is only in documentation; the current 'advanced' which will be to the correct 'settings'
[x] VE at modules/ve-mw/ui/pages/ve.ui.MWSettingsPage.js
[x] VE at modules/ve-mw/ui/tools/ve.ui.MWMetaDialogTool.js T202101
---
[x] Rename filenames used for 'advanced' to //new// 'settings'
[x] Deprecate 'advanced' & rename to 'settings' in JSON files – https://gerrit.wikimedia.org/r/#/c/oojs/ui/+/454363/
[x] Replace 'advanced' across products
[x] MW core RCFilters – https://gerrit.wikimedia.org/r/#/c/mediawiki/core/+/458984/
[x] VE – https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/VisualEditor/+/458988/
[x] CX – https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/ContentTranslation/+/458991/
[x] Echo – https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/Echo/+/458992/
[x] Cite – https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/Cite/+/458993/
[x] TemplateData – https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/TemplateData/+/458997/
[] Remove them