Fix bad type checking to prevent 0 count badge to be shown

What does this MR do?

count provided to the function updating the badge is a string:

• Added docs to this function to make it clear
• Updated tests to check for strings and not numbers
• Exported the gl.text function being used in here (it's the only place it's used)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Tests added for this feature/bug
• Review
  • Has been reviewed by Frontend
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together

What are the relevant issue numbers?

Closes #34841 (closed)