Visit profile through author

• FR-5: The user shall be able to visit a user profile by clicking the creator name of a workout.
• FR-6: The user shall be able to visit a user profile by clicking the creator name of an exercise.
• FR-7: The user shall be able to visit a user profile by clicking the creator name of a meal.

This issue includes adding the owner of exercises and making it possible to set visibility (public, coach, private) on meals. This must be in place in order to visit profiles through the authors.