Notifications: Empty + Loading State Support

[jleandroperez]

Details:

This PR implements a FSM in the Notifications List UI, in charge of rendering Empty State // Sync'ing State // Populated State.

cc @bummytime @mindgraffiti
Thanks in advance!!

Ref. #19

Scenario: Empty State

1. Check out commit c5b699b
2. Launch the app

Verify that the (forced) Empty State renders an Overlay Placeholder, similar to the one we've got in the Orders tab.

Scenario: Sync'ing State

1. Check out commit cc158f4
2. Launch the app

Verify that the (forced) Sync'ing State looks good!

Scenario: Regular Usage

1. Check out the latest commit!
2. Fresh install the app
3. Log into WC
4. Press the Notifications Tab
5. Verify the Sync'ing State looks good
6. Verify the Results are rendered once sync'ing concludes
7. Pull to Refresh
8. Verify the Ghosts are not rendered during Sync

[bummytime]

Looks great @jleandroperez:

✅ Verify that the (forced) Sync'ing State looks good!
✅ Verify the Sync'ing State looks good
✅ Verify the Results are rendered once sync'ing concludes
✅ Verify the Ghosts are not rendered during Sync

Code looks grand. I vote !

[mindgraffiti]

✅ empty state
✅ sync state
✅ device test

❓add FSM meaning to pragma, then !

[mindgraffiti]

What's FSM mean? I'd use // MARK: - Fruitcake Seeking Moo (FSM) Management for the full title here

[jleandroperez]

Thank you both!!