Add slot and enumeration to MetaproteomicsAnalysis to enable separate types of workflows

[kheal]

The upcoming changes associated with MetaproteomicsAnalysis will result in two workflows that are inherently different, one that uses a metagenome that is a result of a DataGeneration process and one that uses a in-silico generated metagenome.

We want to increment these two types of workflows separately and for users to understand (from the WorkflowExecution record) which records are a result of which type of workflow. We also want individually-incremented ids for these workflows so users (and the data portal) do not assume that one is the "most recent".

Our solution is to add a required slot and associated enumeration to the MetaproteomicsAnalysis into class. This will make it clear which of the two workflows were used and allow for incrementing "re-runs" of the each type of workflow separately. All existing records would be migrated to use the enumeration that represents a MetaproteomicsAnalysis uses a metagenome that is a result of a DataGeneration process.

[kheal]

Should be in the schema by Dec 4th for the Dec 16th release (microbiomedata/issues#947)