Java skip thumbnails permission tests: use fake pyramidal images
Instead of relying on the deprecated PixelData service to generate an OMERO pyramid for a fake single-resolution image larger than 3kx3k, use the resolutions key to import a multi-resolution fake image.
SkipThumbnailsPermissionsTest: move the pyramid keys to the suffix
As per https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/io/File.html#createTempFile(java.lang.String,java.lang.String,java.io.File) createTempFile adds internally generated characters between the prefix and the suffix. These characters interfere with the number of resolutions specified by the resolutions key in the filename.
