🎯 Alleviate confusion around "Opened" terminology by changing `opened` to `created` within issuable views

Insight

Users are confused by our use of Opened ## minutes ago in list views. They assume this indicates when the item was literally "opened up"/visited by another teammate or perhaps updated- and not that this is when the item was created.

Supporting evidence

Interview participant: "This is when the issue was last opened or edited"

Dovetail insight link : https://dovetailapp.com/projects/386754d7-5187-4fe1-8a8d-7f1c3e5d4e2f/insights/present/d1c03566-da2c-4548-93b0-0f41d6d419da

Intended users

• Parker (Product Manager)
• Delaney (Development Team Lead)

Action

Change instances of Opened in lists to Created within Epics, Issues, and Merge Requests.

In a list	Within an item

User experience goal

Users understand when an item was created.

Resources

• 🕊 Dovetail project
• 🔍 Research issue

Tasks

• Assign this issue to the appropriate Product Manager, Product Designer, or UX Researcher.
• Add the appropriate Group (such as ~"group::source code") label to the issue. This helps identify and track actionable insights at the group level.
• Link this issue back to the original research issue in the GitLab UX Research project and the Dovetail project.

Further details

We need to make sure we update this in every place it is used.

• MVC 1: !49478 (merged)

  Location	Screenshot
  Issue list
  Issue page
  Issues dashboard
  MR page

• MVC 2

  Location	Screenshot
  Epic header
  Epic - nested epics
  Epic - nested issues
  Epic swimlanes in issue board
  Epic list
  Merge request list
  Merge request dashboard
  Global search (issues/MRs)
  Global search (epics)
  Related issues widget
  "Currently opened" tooltip (issues)
  "Currently opened" tooltip (MRs)
  "Currently opened" tooltip (epics)
  "Currently opened" tooltip (test cases)

• MVC 3 - files identified in #246959 (comment 527962323), to work on in #324855 (closed)

Documentation

What does success look like, and how can we measure that?

Users can differentiate between Updated or edited and Created. We could do some quick validation testing here to see if confusion around this labeling is improved.