Setup project members Vue application

What does this MR do?

Related to #281815 (closed)

As part of &4901 (closed) we are converting the project members view from HAML to Vue. This MR uses the shared code that was setup in &4233 (closed) to setup the Vue application.

Local testing

1. Enable the vue_project_members_list feature flag
   • bin/rails console
   • Feature.enable(:vue_project_members_list)
2. Create a project
3. Navigate to Project -> Members

How to add a group

1. Navigate to Project -> Members
2. Click the Invite group tab

How to add an invited member

1. Navigate to Project -> Members
2. In the GitLab member or Email address enter an email that a user does not already own
3. Click Invite "example@test.com" by email

How to request access to a project

1. Log in (or impersonate) a user that doesn't already have access to the group
2. Navigate to the project overview
3. Click Request access located below the project name

Screenshots (strongly suggested)

Page	Before	After
Members
Groups
Invited
Access requests

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
  • Not needed, behind a feature flag
• [-] Documentation (if required)
  • Screenshots will be updated in separate MR
• 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