Draft: Migrates the buttons in `blob_helper` to pajamas

What does this MR do and why?

Migrates the three different button options in app/helpers/blob_helper.rb to use the Pajamas view component.

They look and feel exactly the same, but the classes are now all updated.

Screenshots or screen recordings

How to set up and validate locally

1. Go to http://gdk.test:3443/root/test-project/-/compare/ and compare two branches with changes
2. Depending on your permissions on that project, you'll see one of the three buttons.
3. Look at different projects or update the logic on line 308 of app/helpers/blob_helper.rb to see the other buttons.

Note: The button to edit a file in a new fork does not work. This is the same before and after these changes. #416199 will address this.

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.