List Users

As an Owner I'd like to be able to list users in order to then manage them

Acceptance Criteria:

1. When admin goes to Administration -> Users he should be directed to Users page.
2. There should be 1 search input with Search button and a list of users under that
3. First 20 users appear on that page by default, there shouldn't be any pagination
4. For every user there needs to be Username, Email and a button Profile to open user profile
5. Admin can search users by username and email
6. Search must be case-insensitive
7. If we search for "ar" we should get both "Arthur" and "Barbara"