Setup Vuex state needed for group members filter bar

What does this MR do?

Setup for #228675 (closed) and small iteration towards !48403 (merged)

In preparation for converting the group members filters to the GitLab UI filtered search component this MR sets up the Vuex state that will be needed. In the process it refactors the initGroupMembersApp parameters.

Screenshots (strongly suggested)

No visual changes yet. For extra context this is what the final product will look like:

Before	After

See below screenshots of Vuex store in Vue dev tools

Members app store

Before	After

Linked groups app store

Before	After

Invited members app store

Before	After

Access requests app store

Before	After

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
  • Not needed, developer facing change
• [-] Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team