Add a build persistence method

[seand7565]

Summary

Provides a wrapper for new, to provide feature parity with creates ability to create multiple records from an array of hashes, using the same notation as the build method on associations.

• Associations can create multiple objects from an array of hashes
• Associations can build multiple objects from an array of hashes
• Classes can create multiple objects from an array of hashes
• Classes can build multiple objects from an array of hashes (<- You are here)

As discussed here: https://discuss.rubyonrails.org/t/allow-activerecord-inheritance-new-to-accept-an-array/80889