suppress user dashboard PCP creation link if resource is inactive

to replicate:

1. create event and enable PCPs
2. select the option to use a contrib page for the PCP
3. disable the contrib page selected
4. login and visit the user dashboard

in the PCP listing, there will be a row representing this PCP (asking if you want to create a page), but the title will be missing.

this is because we:
1. retrieve the list of all contrib pages (which default filters to active)
2. retrieve all PCP blocks – with no respect to whether the target entity is active
3. build the array to be passed to the template, at which point we insert the contrib page title

because the contrib page is not in the list (from 1), the title is empty. what we should do is exclude the row altogether if the target entity is disabled.