Combine the two toolbar components

[MetRonnie]

Problem

We have two toolbar components with some duplicated code:

• src/components/cylc/Toolbar.vue - Used to display the type of view on narrow viewports, and to display a burger button to hide the drawer component.
• src/components/cylc/workflow/Toolbar.vue - Toolbar for the workspace view. Also fulfills the above toolbar's purpose.

Proposed Solution

Combine the toolbars into one component that is always shown. This is more relevant after #1444 has been merged, as the workspace view toolbar will have a user avatar with a dropdown menu, which is not shown on other views.