Prior to this change, a resource handler chain configured with a
`VersionResourceResolver` would add the resource version to the request
attributes when serving that resource. This approach would not work when
a `CachingResourceResolver` is configured and the resource is already
cached. Indeed, that code path is not executed when the resource is
resolved from the cache.
This commit adds a new `VersionedResource` interface that's used by the
`VersionResourceResolver`, adding a `getVersion()` method that returns
the version string for that resource. This way, the version information
is cached with the resource itself and the request attributes are no
longer used for this.
Issue: SPR-13817
473cf9c40e