Migrate authorize GMA account conversion confirmation modal

What does this MR do and why?

Converts authorize Group Managed Account confirmation modal to Vue.

Screenshots or screen recordings

Before	After
Untitled__4_	Untitled__3_

How to set up and validate locally

Group managed accounts is quite tricky to setup. We have a SAML guide but it can be finicky. If you would like a demo let me know and we can set something up. Also the videos above should hopefully be helpful as well.

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 #345127 (closed)