Since we want to conform to dist-spec, sometimes the gc and dedupe
optimizations conflict with the conformance tests that are being run.
So allow them to be turned off via configuration params.
As the number of repos and layers increases, the greater the probability
that layers are duplicated. We dedupe using hard links when content is
the same. This is intended to be purely a storage layer optimization.
Access control when available is orthogonal this optimization.
Add a durable cache to help speed up layer lookups.
Update README.
Add more unit tests.
zot ci/cd tests are too stict, so separate and relax them for compliance
tests.
Location header is set in some cases, but some clarification is needed
in URL construction.
Fix some incorrect compliance tests.
