Use a Class To Pass Around Repository Host Data

[mikeyoung85]

This PR changes the RepositoryHost classes to map their upstream data to a defined Class and pass that Class around instead of unstructured Hash objects. This will help clear up what data is available in the different spots where we are sending upstream repository data around the app. I would like to follow up on this PR with some more changes and add some more util classes that would be responsible for assigning Repository column data to reduce the number of spots where that is happening right now and also split out some of the logic around managing duplicate Repositories that currently exists in the RepositoryHost and Repository classes.

[mikeyoung85]

• changed from class to Struct with some appended method
• updated name to RepositoryHost::RawUpstreamData
• moved the different "factories" into a single converter
• updated method name to create_from_data and updated some callers I didn't see before
• added convenience method for full_name.downcase