After COMPASS-1137 we now have a lifecycle method for consistently accessing the namespace store.

The aim of this ticket is to ensure that the namespace is being accessed consistently throughout Compass via the lifecycle methods.

Acceptance criteria:

• access namespace via lifecycle methods i.e. onDatabaseChanged, onCollectionChanged or directly via onActivated and storing the namespace store from the app registry
• Remove the storing of namespaces from home store and query bar stores
• Changing namespaces should happen directly to through the namespace store