Introduced TransferResource.getResumeOffset() to query position at which transfer started

Introduced utility WorkerThreadFactory to help with name customization and made DefaultMetadataResolver as well as BasicRepositoryConnector make use of it

Introduced AuthenticationBuilder.addHostnameVerifier()

Introduced aether-transport-http and dropped aether-connector-asynchttpclient

Moved NoTransporterException and NoRepositoryLayoutException into org.eclipse.aether.transfer package next to related NoRepositoryConnectorException

Introduced RepositoryLayoutFactory SPI and made basic repo connector use it to retrieve layout

Renamed TransportRequest to TransportTask etc. (requests usually have results, the Transporter methods are void so request/result doesn't really fit)