function to add record type and check digit for record numbers

[crowesn]

Prepend record type code; append 'a' wildcard to accommodate record check number

[jamesvanmil]

There are two types of ids we want, a web_identifier, which doesn't have the check digit, and a public_identifier, which will be used to do manual lookups in Sierra.

There are two parts to implementing this:

1. The *_view tables have the needed information in them, so we can have a universal function included in the relevant models, which constructions the identifiers.
2. We also want this function for the *_record tables, which don't have them. For these, we will parse the class name and make the call to the related *_view models.

We could hard-code some of this information into the models, to reduce calls to the database, but let's see how this approach impacts performance (I suspect it won't involve too much overhead)