pidgin/pidgin

Move PurpleProtocolMediaInterface to its own file.

2020-08-27, Gary Kramlich
96fc115d6c36
Move PurpleProtocolMediaInterface to its own file.

Also cleaned up a few minor things along the way.

Testing Done:
Compile, docs, didn't update the pot file, but did a voice call between pidgin2 and pidgin3.

Reviewed at https://reviews.imfreedom.org/r/90/
#define PIDGIN_ICON 104
#define PIDGIN_TRAY_AVAILABLE_4BIT 105
#define PIDGIN_TRAY_AWAY_4BIT 106
#define PIDGIN_TRAY_BUSY_4BIT 107
#define PIDGIN_TRAY_XA_4BIT 108
#define PIDGIN_TRAY_OFFLINE_4BIT 109
#define PIDGIN_TRAY_CONNECTING_4BIT 110
#define PIDGIN_TRAY_PENDING_4BIT 111
#define PIDGIN_TRAY_INVISIBLE_4BIT 112