When you are the last owner of a group or the owner of a project,
you don't have the :update_<source>_member / :destroy_<source>_member
abilities, but you do have the :admin_<source>_member so you should
be able to see your members access levels.
Signed-off-by: NRémy Coutable <remy@rymai.me>

Signed-off-by: NRémy Coutable <remy@rymai.me>

+ Move 'Edit Project/Group' out of membership-related partial
+ Show the access request buttons only to logged-in users
+ Put the request access buttons out of in a more visible button
+ Improve the copy in the #remove_member_message helper
Signed-off-by: NRémy Coutable <remy@rymai.me>

Signed-off-by: NRémy Coutable <remy@rymai.me>