Coming soon: settings page

[ramonjd]

As a use I should be able to switch coming soon mode on and off in my site settings.

Since sites are "public" in Coming Soon, if the site is marked as private we should switch to public (but with search engine indexing disabled) if the user toggles Coming Soon mode.

From the settings section we could provide a link to the coming soon page (to edit) (?)

[lsl]

cross linking / D45700-code / #45167

[lsl]

Replace #45167 with:

• Add/comingsoon v2 calypso #45606 - calypso changes
• Add/etk coming soon v2 #45581 - etk changes
• add setter and getter for comming soon setting to api #45604 - settings api filters

[lsl]

Bunch of change ups on this code:

• Settings page changes: Mostly implemented in Update/remove coming soon option #46034
• But changing again in Make Coming Soon option always show regardless of v1/v2 #46119

A lot of the og work is now in #45896 that will likely need to be broken down further.

[ramonjd]

Merged