Add type on class PlannedProcess

[sujaypatil96]

Children of class PlannedProcess (Pooling, Extraction, LibraryPreparation) are being used extensively in the NEON metadata ingest pipeline to create instances of above mentioned processes.

It is useful to know the type of instances being created, like how we indicate for Biosamples that they are of type nmdc:Biosample. Similarly, it is useful to annotate instances of PlannedProcess objects (and their children) with type as well. For example, Pooling process instances will have type nmdc:Pooling, Extraction process instances will be of type nmdc:Extraction and so forth. This is useful redundancy to have, because it helps while writing queries against the database.

So we are requesting a modeling change where you assert the slot type on PlannedProcess, which will carry over into its child classes as well.

[turbomam]

OK. What should the range be? There are type values in the data already that are nmdc-schema class URIs, enumerate values, or free text string. My preference is for an enumeration in this case, but maybe we can make stub classes in the future.

[sujaypatil96]

Related to #1030

[kheal]

type is now a slot on NamedThing which is the parent class of PlannedProcess on Berkeley fork.