Improve Quick Publish Error handling

[#1]

Request for Feature Enhancement (RFE) Summary:	When doing a quick publish in AEM 6.5.21 of a page that refers to a template that contains policies for components, the publish action fails (without any error message) when there is an issue when the cq:lastReplicated property is missing on a policy, and the cq:lastReplicationAction is set to Activate. Upon inspection of the logs, it seems like there is a NPE in the ActivationReferenceSearchBuilder. When manually replicating the default policy, the issue resolves and the replication works, as the reference search no longer errors with a NPE.  I would expect either an error message, replication to skip the reference, or some more Null safety checks in the reference search service.
Use-case:	Users cannot Quick Publish content that has issues with related content missing cq:lastReplicated property.
Current/Experienced Behavior:	It's very difficult for developers to debug this as we only have an internal NPE without any reference to what is the error. The ActivationReferenceSearchBuilder could point to related content, content fragments, experience fragments, but in this case there is an issue with a linked component policy on the template.
Improved/Expected Behavior:	At least: an error message in the user-facing quick publish dialog. Currently the behavior is a red Warning icon without any text.  Secondary: a more relevant error message: instead of a run-time NPE, a dedicated exception or a warning/debug log would be nice.
Environment Details (AEM version/service pack, any other specifics if applicable):	AEM6.5.23
Customer-name/Organization name:	Nationale Loterij
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Code package (if applicable):