Instead of emitting a CSS `counter-reset` for each footnote marker**Context:**
To allow localization and customization of footnotes and backlink markers Parsoid introduced CSS `counter-`styles, while on the HTML output it's emitting only integer numbers in both cases. Parsoid should instead emit the literal text such as `[3]`, Parsoid should emit literal text such as `[3]` or `[٣]``[٣]` or `a` according to content language, according to content language and custom groupcustom group or backlink marker configuration. This is already how the legacy parser works.
Many sites are usingcurrently need to set these CSS customizations for these numbers, and this must be considered during migration to explicit numberingso that their Parsoid output aligns with the legacy output. When this epic is complete, the customizations should be removedThese customizations need to be considered when migrating. The big relief here is that custom groups already need to be customized using all mechanisms, so we can rely on eg. the i18n message being available.When this epic is complete, Example custom group labels: [[ https://fa.wikipedia.org/wiki/%D9%85%D8%AF%DB%8C%D8%A7%D9%88%DB%8C%DA%A9%DB%8C:Cite_link_label_group-persian-alpha | fa:MediaWiki:Cite link label group-persian-alpha ]]the CSS customizations could be removed while having the parsers aligned on the footnote and backlink rendering outputs.
**Motivations**:
* Makes it possible to do localization and alternative counter markers along with programmatic document rendering.
* Consolidate to a single mechanism.
* Plaintext compatibility (eg. copy and paste).
* Consistency in VE (TBD: explain in more detail)
* Prerequisite implement sub-referencing
**Historical notes**:
* The legacy Cite parser has always used explicit numbering.
* CSS `counter-reset` numbering was first introduced into Parsoid in {T86782} to work around customization. At the time, Parsoid was written in JS and couldn't conveniently tap into the PHP i18n which provides custom numbering.
**Out of scope**: some related tasks will be implemented separately. Experience gained during this task can be applied to the other issues, we'll refine the other tasks' descriptions to add this info.
* {T370883}