Core: Adjust namespace separator in TestRESTCatalog

[gaborkaszab]

The resource paths used for comparisons in the REST catalog test use different namespace separator than the test REST catalogs. This PR brings them in line.

[gaborkaszab]

When we get the path in the REST catalog tests we use e.g. TestRESTCatalog.RESOURCE_PATHS that uses %1F as namespace separator. However, the test REST catalog use %2E as NS separator, so verification on paths being called fail if there is a multi-level namespace, or metadata table name involved. One workaround can be to create a new ResourcePaths instance with the particular NS-separator for each such test (one example is in testNotModified()) but I think it's more future-proof to configure the RESOURCE_PATHS member to use such separator. For instance I ran into this issue when rebasing my freshness-aware loading PR and then some of my path checks started failing.

[gaborkaszab]

cc @nastra as the owner of the configurable namespace separator change

[gaborkaszab]

Thanks for reviewing, @nastra !