Re-ordered types, added conformances

0.2.0

I might regret this, but I cascaded the types to make them distinct from other types in usage. Especially as a data transfer object (DTO), it was getting rough to determine which "kind" of thing I was working with - the local models, or the DTO.

• SearchResult
• SearchResult.Package
• SearchResult.Package.PackageId

Additionally, added the obvious conformances to make them easier to work with:

• Codable, Identifiable, and Hashable across the board
• Comparable for PackageId (to provide stable sort ordering)
• CustomStringConvertible for PackageId to make it easier to compose it into strings.