feat(bar): add locked container widget, use accent colour for icons

This commit adds a new komorebi widget to indicate whether or not the
focused container is locked.

This commit also includes an icon colour change on the layer and layout
widgets to the accent colour.

The commit also renames the locked_window widget to locked_container as
it is more suitable.

PR: #1394

schema.json

@@ -354,6 +354,45 @@
               "format": "color-hex"
             }
           ]
+        },
+        "unfocused_locked": {
+          "description": "Border colour when the container is unfocused and locked",
+          "anyOf": [
+            {
+              "description": "Colour represented as RGB",
+              "type": "object",
+              "required": [
+                "b",
+                "g",
+                "r"
+              ],
+              "properties": {
+                "b": {
+                  "description": "Blue",
+                  "type": "integer",
+                  "format": "uint32",
+                  "minimum": 0.0
+                },
+                "g": {
+                  "description": "Green",
+                  "type": "integer",
+                  "format": "uint32",
+                  "minimum": 0.0
+                },
+                "r": {
+                  "description": "Red",
+                  "type": "integer",
+                  "format": "uint32",
+                  "minimum": 0.0
+                }
+              }
+            },
+            {
+              "description": "Colour represented as Hex",
+              "type": "string",
+              "format": "color-hex"
+            }
+          ]
         }
       }
     },