Major refactor of workspaces api

+ The "main" workspace is no longer treated especially, and can be
  renamed or deleted. Fixes issue mentioned in #200.
+ In the disastrous event that there are no workspaces left, a main one
  is generated and switched to. Under no circumstances should the use be
  left in the nil perspective!
+ Fix the :tabr[ename] ex command throwing argument errors.
+ Refactored most workspace functions.
+ New command: +workspace/close-workspace-or-frame, which is bound to
  C-S-w in my private module.

modules/private/hlissner/+bindings.el

@@ -37,7 +37,7 @@
  "M-t"    #'+workspace/new
  "M-T"    #'+workspace/display
  "M-w"    #'delete-window
- "M-W"    #'delete-frame
+ "M-W"    #'+workspace/close-workspace-or-frame
  "M-n"    #'evil-buffer-new
  "M-N"    #'make-frame
  "M-1"    (λ! (+workspace/switch-to 0))