Generalize/simplify handling of common card info (e.g. app version)

Card:
* Add parseCardInfo() for parsing the common card infos APPVERSION,
  CARDTYPE, and CARDVERSION
* Add cardtype() and cardVersion() returning the parsed card info
* Add displayAppVersion() and displayCardVersion() returning nicely
  formatted version numbers

OpenPGPCard:
* Remove unused mIsV2
* Remove obsolete setSerialNumber() overload and obsolete cardVersion()
  and mCardVersion; the app version (confusingly named mCardVersion)
  is now read from the card info by the base class
* Rename setKeyPairInfo() to more appropriate setCardInfo() (also used
  for PIVCard)

PIVCard:
* Parsing of APPVERSION is now done by the base class

ReaderStatus:
* handle_openpgp_card: Use "LEARN --force" instead of
  "LEARN --keypairinfo" to also get common card infos

ChangePinCommand, PGPCardWidget:
* Simplify checks for certain app versions

PGPCardWidget, PIVCardWidget:
* Use Card::displayAppVersion() to get app version for display