[ENH] Ability to set "Site Default Theme" or recognize which is the default when reviewing/creating new pages/page settings.

[thabaum]

Describe the enhancement

Ability to set "Site Default Theme" or recognize which is the default when reviewing/creating new pages/page settings.

I always find it difficult to know which is actually the site default theme

• Default Theme should only be on the "Site Theme selected" and only say "Default Theme" or "Current Site Theme" to help us know how to set a page back to the site default without having to set it.

Maybe a checkbox for "Use Site Default" and if unchecked opens up options to select?

Maybe Oqtane is already supposed to handle this, if so this should be renamed to [BUG]

[thabaum]

@sbwalker thank you!