Add "max zoom" value into camera capabilities.

[ghost]

Hello, guys!

I think it will be useful if you add "maxZoom" value into camera capabilities. Little use-case: you want to create pinch-zoom camera view, and you need max zoom level value for correct zoom step value calculations according to fingers travelling distance calculations.

[ghost]

@Diolor , thanks for the review! I've made several changes according to your request, please check it.

[Diolor]

Thanks! It will be in the next release. If you need it immediately you can use a -snapshot FA version

[ghost]

Thanks!

[ghost]

@Diolor , hello! Can you tell me, when you planned to release the new version of Fotoapparat with this functions?..