DS: Allow a condition towards a framework property

[kwin]

Sometimes a declarative service should only be active in case a framework property is set or set to a specific value. For a concrete use case look at https://issues.apache.org/jira/browse/SLING-9648?focusedCommentId=17173899&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-17173899

[tjwatson]

I think this could be solved by the support coming for the Condition specification in R8 in DS. One could easily register a Condition to activate components based on framework launch properties.

[bjhargrave]

We should use Conditions but have the Condition Factory support registering Conditions based upon properties presence/values.

[juergen-albert]

I added it as a todo for the Condition Factory Spec