add a way to expand/collapse all methods

## Add a way to expand/collapse all methods

### Acceptance Criteria
1. Button exists to expand/collapse all methods.
2. If any one method is closed then the button will read "expand" and its function will be to expand all methods which are not currently open.
3. If ALL methods are open then the button will switch to read "collapse" and its function will be to collapse all methods.
Space after `!` (twice above)