add httpsPost to CommunicationsTransportMethod list

[haeckerbaer]

httpsPost is not available in SIRI XSD

[haeckerbaer]

[haeckerbaer]

not only add httpsPost but update in general. However, this is only referenced in AbstractFunctionalServiceCapabilitiesResponse which is probably not used in the real world

[DohmenClaus]

To be clarified:
Is this used at all and should be supported in the SIRI Protocol?
-> if no: remove completely
-> if yes: complete revision needed, separation of concerns: transport vs. method