Add strip_workspace_name

See the issue #3163 (https://github.com/i3/i3/issues/3163).

Add strip_workspace_name to strip off the workspace name.

parser-specs/config.spec

@@ -455,6 +455,7 @@ state BAR:
   'binding_mode_indicator' -> BAR_BINDING_MODE_INDICATOR
   'workspace_buttons'      -> BAR_WORKSPACE_BUTTONS
   'strip_workspace_numbers' -> BAR_STRIP_WORKSPACE_NUMBERS
+  'strip_workspace_name' -> BAR_STRIP_WORKSPACE_NAME
   'verbose'                -> BAR_VERBOSE
   'colors'                 -> BAR_COLORS_BRACE
   '}'
@@ -555,6 +556,10 @@ state BAR_STRIP_WORKSPACE_NUMBERS:
   value = word
       -> call cfg_bar_strip_workspace_numbers($value); BAR
 
+state BAR_STRIP_WORKSPACE_NAME:
+  value = word
+      -> call cfg_bar_strip_workspace_name($value); BAR
+
 state BAR_VERBOSE:
   value = word
       -> call cfg_bar_verbose($value); BAR