Add ability for the new dropdown to take a partial and load modal

What does this MR do and why?

• Breaks up !111485 (merged) into more vertical/refactoring chunks for ease of review and separation of concerns.
• Loads invite members modal in a more global context to allow only one instance to be in the DOM.
  • solves issues of having more than one modal selector in the DOM when we only really need one. This will be more evident in use in !111485 (merged)
  • How are we sure all of these invite modal launches are covered here? - I made sure of it in !111976 (merged)
• Extends the new dropdown menu to allow for use of partials instead of rendering only links.
  • this code extension will allow us to add new dropdown functionality for invites in !111485 (merged)
• Prefers project over group for menu items when both are defined.
  • this is general change/fix - condition isn't hit in code today, but if it is in the future, this is the way we would likely expect it to perform.
• Defines that the only place we want to allow page refresh after invite modal submitting is in the index actions for members page.
  • This allows us to have multiple 'invite' buttons on a page that may appear on other pages like the top nav invite in !111485 (merged) to refresh only when on the members page.
• Refactors the emoji concept into reuse of the word icon as a more general term instead of having both.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #338506