QXmpp 1.8.0

• QXmpp now requires C++20
• Fix connection to next SRV record if connection to first address fails (@lnjX, #644)
• Implement XMPP over TLS ("direct TLS" instead of STARTTLS, XEP-0368) (@lnjX, #642)
  • Support of protocol/server name multiplexing, ALPN and SNI extensions
• New Bind 2 support (XEP-0386) (@lnjX, #614)
  • Client and server support of resource binding through SASL2 + Bind2
  • Resource prefix can be configured in QXmppConfiguration
  • Setting of Client State Indication (CSI) initial state on connection
  • Enabling of Stream Management (through Bind 2) and stream resumption (through SASL 2)
  • Enabling of Message Carbons (through Bind 2)
• Support FAST, token-based authentication (XEP-0484) (@lnjX, #630)
  • Offers single round trip authentication (but doesn't replace strong authentication methods
    like SCRAM+password)
  • FAST tokens (and other credentials) can be stored permanently via QXmppCredentials
  • Tokens are generated if a SASL 2 user agent is set and FAST is not disabled in the config
• New QXmppUri for parsing XMPP URIs (XEP-0147) (@lnjX, #641)
• New AccountMigrationManager for importing and exporting account data (@lnjX, @pasnox, #623)
• Message: Parse all stanza IDs (XEP-0359) (@lnjX, #638)
• CSI state is automatically restored across reconnects, also without Bind 2 or stream management (@lnjX, #622)
• Use smaller stream management acks instead of ping IQs if possible (@lnjX, #625)
• Moved STARTTLS handling into the core client again (was in client extension) (@lnjX, #627)
• VCardManager: New task-based API (@lnjX, #623)