Allow specifying a version of the default-ui in the war pom instead of always using the version of the war

Consider the following usecase:
I have a maven project where I overlay the standard enterprise war with some dependencies to produce another war. This war is versioned independently from of xwiki-enterprise.

The way the distribution wizard works right now is that when it checks to see if I need to upgrade the UI installed for this war, it checks the properties in the pom (xwiki.extension.distribution.ui, xwiki.extension.distribution.wikiui and xwiki.extension.distribution.workspaceui) but it always uses the war version as a version of these UIs. In case of a custom war this is a bit of a pain because it means that I need to make a custom xar as well, only for using the standard UI at the good version as dependency.

I would like to be able to specify a version for these UIs, in a separate property (e.g. xwiki.extension.distribution.ui.version, xwiki.extension.distribution.wikiui.version and xwiki.extension.distribution.workspaceui.version). In order to change as little as possible the existing, if this property is missing, DW could always fallback on the war version, and this property would always be missing in the default war.