Aligning the Publication models with Kotlin

[mickael-menu]

readium/r2-shared-swift#83, readium/r2-streamer-swift#153 and readium/r2-navigator-swift#106 partially fix this issue, I'll strike the items progressively.

This Kotlin PR refactored the Publication models and introduced a lot of changes needing to be replicated on Swift:

• Add missing values in ReadingProgression
• Fix the computing of the ReadingProgression (see readium/architecture#113)
• Review the Date parsing from ISO 8601
• Use an interface for PositionListFactory and add unit tests for each format
  • (POSTPONED: Let's see how the Streamer API will look like first)
• Use a dictionary for LocalizedString
• Add the Presentation Hints extension
  • Move Page and Orientation from Properties to Presentation
  • Remove scrollContinuous
• Publication
  • Rename addSelfLink to setSelfLink
  • Rename ContentLayoutStyle to ContentLayout and add tests
  • Rename resourceWithRelativePath to resourceWithHref
  • We should not filter out Link without a rel here: https://github.com/readium/r2-shared-swift/blob/cb2420f4dee0cc8cd55dce59329ab1f87cca01af/r2-shared-swift/Publication/Web%20Publication/WebPublication.swift#L51
• OPDS
  • Move OPDSPrice, OPDSAcquisition to the OPDS folder
  • Add missing OPDS objects and extensions
  • Rename indirectAcquisition to indirectAcquisitions
• EPUB
  • Remove media-overlay from the EPUB extension and from Link
  • Move metadata.layout to metadata.presentation.layout
  • Rename listOfAudioFiles to listOfAudioClips, and listOfVideos to listOfVideoClips
  • Remove EPUBRendition and use EPUBLayout instead
  • Move EPUBLayout.fromEPUB to the EPUB parser
  • Extract the encrypted object to a new Encryption extension
    • Rename original-length to originalLength (but still parse the old one for backward compatibility)
  • (streamer) Don't parse <readingOrder>, only <spine> is valid in the OPF
  • in otherMetadata, resolve dc metadata to the dcterms UR.
• Locators:
  • Add HTML extension
• Review the new unit tests in r2-streamer-kotlin, in particular:
  • Fix OEBPS 1.2 DTD
  • Additions in NCX
  • OPF tests regarding the EPUB versions