RFC4466 (2006): Collected Extensions to IMAP4 ABNF

[nevans]

Supporting RFC4466 as well as the basic ABNF in RFC3501 will give significant forward compatibility, allowing us to partially parse some other extensions which we don't (yet?) otherwise support. Additionally, RFC4466 support is necessary for RFC9051.

• Parse unknown or unsupported extensions using RFC4466 tagged-ext syntax
  • Parse tagged-ext-val (done as part of ⚡ Better Faster Cleaner STATUS parsing #225)
  • Add ExtensionData (done as part of ⚡ Better Faster Cleaner STATUS parsing #225)
  • Add TaggedExtensionData (with #to_hash) #127
  • Add ExtensionDataList (with #to_ary) #128
  • Add UnparsedData (with #to_str) #129
    (also usable for non-RFC4466 extension data)
• RFC4466 2.1: Optional Parameters with the #select/#examine Commands
  • Add arbitrary kwargs to #select/#examine, using select-params syntax (RFC4466 tagged-ext) #124
  • Add kwargs to #select/#examine for existing select-param extensions
    • Add condstore kwarg to #select, #examine (RFC7162, CONDSTORE) #122
    • Add :qresync kwarg to #select, #examine (RFC7162) #123
• RFC4466 2.2: Extended #create Command
  • Add arbitrary kwargs to #create, using create-params syntax (RFC4466 tagged-ext) #126
  • Add kwargs to #create for existing create-param extensions
    • Add :use kwarg to #create (RFC6154, SPECIAL-USE) #125
• RFC4466 2.3: Extended #rename Command
  • Add arbitrary kwargs to #rename, using rename-params syntax (RFC4466 tagged-ext) #130
• RFC4466 2.4: Extensions to #fetch and #uid_fetch Commands
  • Add arbitrary kwargs to #fetch/#uid_fetch, using RFC4466 tagged-ext syntax #133
  • Add kwargs to #fetch/#uid_fetch for existing fetch-modifier extensions
    • Add changedsince kwarg to #fetch/#uid_fetch (RFC7162, CONDSTORE) #132
    • Add :vanished kwarg to #fetch/#uid_fetch (RFC7162, QRESYNC) #131
• RFC4422 2.6: Extensions to #search Command
  • RFC4422 2.6.1: Extended SEARCH command #115
    • Add arbitrary return opts to #search, using search-return-opts syntax (RFC4466 tagged-ext)
  • RFC4422 2.6.2: ESEARCH untagged response #121
    • Parse RFC9051 esearch-response and search-response-data #120
    • Parse all existing search-return-data extensions directly
• RFC4422 2.7: Extensions to #append Command
  • Support BINARY extension to #append (RFC3516, RFC4466) #535
  • RFC7888 (2016): LITERAL+ (obsoletes: RFC2088 1997) #537
  • [RFC3502] Support MULTIAPPEND extension (also RFC4466) #536