Process image resolving on Windows

If user tries to retrieve process image stored in specific package from Kie server on Windows then Kie server returns null instead of the image.

It seems to be caused by resolving of process directory [1]. Resolved process directory path contains OS specific separators (
on Windows), those aren't correctly processed by kie module searching for image.

[1] https://github.com/kiegroup/droolsjbpm-integration/blob/ce83004e3fc49d1f992bbb90dbd18b8fc0972858/kie-server-parent/kie-server-services/kie-server-services-jbpm-ui/src/main/java/org/kie/server/services/jbpm/ui/img/ImageReference.java#L54