Ability to handle multiple modems on a single device

[DomAmato]

Is your feature request related to a problem? Please describe.

Currently the SDK always defaults to the first modem it can find and knowing what modem options exist could be useful if one modem is preferred over another.

Describe the solution you'd like

Can keep the current method for general use but also enable the ability to enumerate and choose modems that are attached.

Describe alternatives you've considered

It seems possible to specify the make of the modem but if there are two of the same kind it would always default to the first one it finds.

Additional context