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