Update ee MR widget to use best practices

What does this MR do and why?

Update ee MR widget to use best practices

• remove vm set
• use shallowMount where possible
• remove vm expectations
• simplify tests

What does this MR not do and why?

• fixes every issue in this file because there are a lot of them
• I will continue to use the same issue and https://gitlab-org.gitlab.io/frontend/playground/vue-compat-scanner/ to track what is left

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.

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 #391146 (closed)