Add workout templates that can be used to create workouts with exercises added by default

[brianwalborn]

• A Templates tab should be added to the Library
• Templates are a way to "quick start" a workout and include exercises (and sets & weight if desired)
• The UI should be similar to the existing workout UI, but without the info elements at the top
• Templates should have a title
• Similar to the past workouts page, templates in the library should have the muscles worked as tags (pills), but not have Volume or Duration