Wp-calypso: FSE: provide an easy way for HEs to detect FSE sites in Blog RC

[vindl]

We have no way of differentiating FSE from normal sites in Blog RC now. This can be inferred by presence of full-site-editing sticker and Maywood theme being active, but it would be nice to make this more obvious.

cc @apeatling @selectedselections

[mattwiebe]

D33808-code will do this

[noahtallen]

@selectedselections this adds an item to the "blog stickers" section of the blog RC:

The user will see FSE flows:

The user would see FSE flows if they switched to the Maywood theme again:

If the user has no way of ever seeing FSE, then there will be no info here.

[selectedselections]

Alright! This looks great! I think this is exactly what we need. Thank yall so much for your work on both of these!

[mattwiebe]

@selectedselections this has been shipped - thanks for throwing in the screenshots @noahtallen