Get rid of Owner concept

[wrigleyDan]

Describe the bug
Remove the concept of Owners from Quepid. It's a relict from old times that does not provide any additional value.

To Reproduce
n/a

Expected behavior
Every user that creates a team should automatically be a member of that team.

Screenshots
n/a

Additional context
n/a

Tasks:

• Write a migration script that ensures that every owner of a case is also a member of that case to facilitate updates.
• Write a migration script that drops the teams.owner_id column.
• Delete from teams/show.html template the reference to the change-team-owner component.
• Delete the change-team-owner component.
• Update team.rb and user.rb relationships.
• Update team listing views; both owner_id and teams I own.
• Remove "Owner" badge on profile.
• Check seeds script to ensure owner is member.