Merge release 1.8.4 into master (#4797)

* Update version number (#4759)

* update copyright (#4775)

* Observe changes to sub-objects in flexible layouts. (#4780)

* Get child of flex layout as mutable if possible

* Fix bug when no default notebook defined

* Follow domain object changes for Independent time conductor (#4783)

* Track if domain object changes when independent time conductor is in use.

* fix typo when using fallback template (#4784)

Co-authored-by: Scott Bell <scott@traclabs.com>
Co-authored-by: Andrew Henry <akhenry@gmail.com>

src/plugins/timeConductor/ConductorInputsFixed.vue

@@ -95,6 +95,11 @@ export default {
             isUTCBased: timeSystem.isUTCBased
         };
     },
+    watch: {
+        keyString() {
+            this.setTimeContext();
+        }
+    },
     mounted() {
         this.handleNewBounds = _.throttle(this.handleNewBounds, 300);
         this.setTimeSystem(JSON.parse(JSON.stringify(this.openmct.time.timeSystem())));