Implement resolution scope into RefResolver
Change resolution scope when resolving a remote schema
Refactor RefResolver to use 'resolving' method as a context manager
which changes the scope and returns referenced schema
Make sure remote refs are cached for the duration of validation
within their scope
Switching to actual subtree.
Squashed 'json/' content from commit 29e2c7c

git-subtree-dir: json
git-subtree-split: 29e2c7c241f1d508d584b412ba8fccd6c25e7f14
Merge commit '9fbaf7ea41abaeed40742ab1f8b3519c3e5954bb' as 'json'
Merge remote-tracking branch 'gazpachoking/ref_resolution_scope'
Flakes.
Allow ignoring tests, prep for adding refRemote.
Test remote references.