Center align members table rows

What does this MR do and why?

Related to #416369 (closed)

Vertically centers rows in the members table

Screenshots or screen recordings

Members

Before	After

Groups

Before	After

Invited

Before	After

Access requests

Before	After

How to set up and validate locally

How to add a group to the Groups tab

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

How to add an invited member to the Invited tab

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

How to add a user to the Access requests tab

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

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.