Implement pre-filtering on data types

[guignonv]

Some data types may need to be pre-filtered. For instance germplasm and sample share the same table but differ by type_id. The type_id is filtered on the search call but not when an identifier is provided. Therefore, the sample/{sampleDbId} will work with a germplasmDbId while it should not because no-prefiltering occurs.
Another case is the traits/ call that will list all the CV terms, even non-trait ones.
Pre-filtering should be specified in the brapi_get_data_mapping() call.

[guignonv]

Fixed by commit 027bf89.