Split Pattern Translations into two multiple GlotPress projects

Describe the bug
Currently all Pattern strings are added to the https://translate.wordpress.org/projects/patterns/core/ GlotPress project.

This was a decision made here and here.

Due to the number of possible patterns, and user-submitted strings, it's going to grow quickly and become hard to prioritise certain patterns over another.

I believe we should split patterns strings into two GlotPress projects: Core (WordPress.org "official" patterns) that should get a high-priority on translations, and Community (Every string ever submitted by all creators).

Additionally, it may make sense to create a third project for either Popular Patterns, or for "Common Strings" (Either popular strings, or a set of 'suggested' strings for use within patterns).

Note: GlotPress projects do already have a 'priority field' for individual strings, which could be used here as well, but I feel that's more relevant when it's used for a small / select few strings within a project, not as a blanket Official-vs-Community distinction.