Add assistant to the pog plugin manifest.

[Issue: ]
Continue auto discharge if some POs unsupported.

[Issue: ]
Improve UI for unsupported POs.

* Show the PO predicate for unsupported POs
* Generate and export supported POs for partially supported models.

[Issue: ]
Fix iteration of param types in implicit funcs.

[Issue: #299]
Merge commit 'aeb34dfed7b967a0fb99fb54a91b3418c5f16b65' into rjp