Fix: locale issue on issue page header actions

What does this MR do and why?

In the current version of our issue actions, we have serval places that used the raw issueType instead of the IssuableTypeText, and there were 2 implementations for this. In this MR:

• Unified the reference and implementation of issueTypeText.
• Enhanced the IssuableTypeText against the types defined in the constant file.

/cc @prajnamas @qk44077907 @orozot @fenyuluoshang

/cc looping @deepika.guliani here since you modified the file before.

Fix: locale issue on issue page header actions

• Unify the header action texts referencing.
• Enhance the IssuableTypeText.

Changelog: fixed

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

1. Set your local preferred locale to any language other than English.
2. Go to any issue
3. Toggle the header action section.
4. Turn your website into mobile version, then checkout the dropdown area.

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.