Precompiling all CBN's upon importing new library

This step is necessary to report any new warnings that may arise out of namespace conflicts arising after importing a new library. 
This is also necessary for the new [changes being made to resolve namespace conflicts] (https://github.com/DynamoDS/Dynamo/pull/3255) that embeds namespace information to the DYN file and reads from it to do the resolution.

@junmendoza @ke-yu please review.