REFACTOR: User menu profile link for extensibility (PR #8039)

CONTEXT: Quick access to bookmarks and messages on user menu

[Making the profile link a quick access tab] will require a minor PR to core first.

This minor refactor extracts UserMenuLinks#profileLink & UserMenuLinks#linkHtml to allow plugins / themes to control the profile link definition, and more importantly, how it is rendered.


You’ve signed the CLA, xrav3nz. Thank you! This pull request is ready for review.

Thanks for the review and ready to merge!

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Looks good to me!!!