Quality/language/release profile and quality definition parser fixes

[Callum027]

Implement additional validation of quality, language, release profile and quality definitions to ensure proper error checking and consistent value parsing. Also fix a number of small bugs.

• Refactor the quality profile root validator to be easier to understand, and include setting upgrade_until to None if upgrades_allowed is False to ensure Buildarr ignores the remote value when upgrades are disabled
• Refactor the quality profile remote map entries to be easier to understand
• Sonarr requires a valid value for upgrade_until even if upgrading is disabled, so fix upgrade_until encoding when set to None by sending the value of the highest enabled quality instead (this fix applies to both quality and language profiles)
• Add the same checks that are used in quality profiles into the language profile parser:
  • upgrade_until is required if upgrades are enabled
  • Set upgrade_until to None if upgrades are disabled
  • Reject duplicate language declarations
• Enable validation of in-place assignments on release profiles and quality definitions, to ensure the values loaded from TRaSH-Guides profiles are valid, but also allow processing validators (e.g. sorting on release profiles) to run
• Simplify release profile preferred word sorting function
• Fix incorrect syntax in language profile definition examples in documentation