Adds ability to specify value metadata on the key after a colon

in Args class, for example:

--my-key:SomeMetadata my-value
Ability to provide global overrides/defaults to batch import input entities

specifically additive labels to nodes, so that nodes in a specific input
group will always get a certain set of labels, in addition to whatever
they individually specify. And ability to specify default relationship
type for input relationships if missing.
Merge pull request #3435 from tinwelint/2.2-bip-input-entity-decorator

Batch import input entity decorator