791ebf4f78
This PR contains the work done to implement the `UserAgentMiddleware` middleware that includes user agent information into a header of the requests sent by the `Client` type, as defined in the [Discogs documentation](https://www.discogs.com/developers/#page:home,header:home-general-information). For this purpose, the `CamelCaseValidationRule`, `SemanticVersionValidationRule` and `URLValidationRule` types were implemented and integrated into the existing `ValidateInputUseCase` type. Reviewed-on: #6 Co-authored-by: Javier Cicchelli <javier@rock-n-code.com> Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>