Remove references to wrapper.vm

What does this MR do and why?

Fixes some Vue 3 spec violations:

• Use the local reference to the store, instead of from the component: wrapper.vm.$store -> store
• Validate the different empty states using test IDs instead of checking the component internals

How to set up and validate locally

yarn jest ee/spec/frontend/issues_analytics/components/issues_analytics_spec.js

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 #413331 (closed)