[PHY] Get/Set modem

[jgromes]

This PR adds an interface to get and set modem type (LoRa, FSK or LR-FHSS) through PhysicalLayer. Needed for LoRaWAN to support FSK and LR-FHSS uplinks.

EDIT: Also drupped Arduino Uno from the CI build list, since the library is too large to build on a large portion of the examples.

[lyusupov]

Jan,
use of too much generic symbols here:
https://github.com/jgromes/RadioLib/blob/master/src/protocols/PhysicalLayer/PhysicalLayer.h#L138-L140

/*!
  \enum ModemType_t
  \brief Type of modem, used by setModem.
*/
enum ModemType_t {
  FSK = 0,
  LoRa,
  LRFHSS,
};

- causes namespace conflict with other software at build time

Could you, please, consider to replace it with more RadioLib specific names, such as:

/*!
  \enum ModemType_t
  \brief Type of modem, used by setModem.
*/
enum ModemType_t {
  RADIOLIB_FSK = 0,
  RADIOLIB_LoRa,
  RADIOLIB_LRFHSS,
};

Thank you!

[jgromes]

@lyusupov That's a good point actually, it's fixed in 4564d87 - thanks!