is Model Provided
Verifies whether a model is available based on the given identifier.
Return
true if the model corresponding to the given identifier is available, false otherwise
Parameters
model Identifier
the identifier of the model to check availability for
Returns true when a model is provided at the unambiguous (bundleId, modelId) pair. Distinct from the single-string isModelProvided, which uses the flat byModelId lookup with first-wins shadowing.