Add badge for invited user

What does this MR do and why?

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/334294

This is a takeover of a community contribution: !65410 (closed)

This MR adds a badge that indicates whether an invited user is awaiting signup.

From our docs: https://docs.gitlab.com/ee/user/group/#add-users-to-a-group

There are 3 different states of a user in the invited tab, and we thought that all of them should have a badge:

• Have not yet accepted the invitation: Awaiting user signup <---- Added in this MR
• Are waiting for approval from an administrator: Pending owner approval
• Exceed the group user cap: Pending owner approval

Screenshots or screen recordings

Before	After

How to set up and validate locally

1. Go to Menu > Groups > Your Groups
2. Choose a group or create one
3. Go to Group information > Members
4. Click on the tab invited. URL: /groups/<group name here>/-/group_members?tab=invited
5. Invite a new member with an email that doesn't have an account yet (e.g.: team-member1@gitlab.com)

There should be a badge on the invited column with the text Awaiting user signup

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.