Instead of overloading getOutboundCount() with a magic sentinel value,
add a dedicated getOutboundTotal() method to the PacketManager interface
that returns the total queue size without time filtering.
This eliminates the fragile convention that caused the regression and
makes the two operations — time-filtered count vs total count —
explicitly separate in the API.
This change counts when readData returns an err code other than RADIOLIB_ERR_NONE. In most cases this is going to be a CRC error. This counter is exposed in the `stats-packets` command, and in the repeater stats payload (4 additional bytes to the payload, which is now 56 bytes with this change. My incompetent robot claims the total payload size is 96 bytes (unverified but probably close).
- Added formatStatsReply, formatRadioStatsReply, and formatPacketStatsReply methods in MyMesh for both simple_repeater, simple_room_server, and simple_sensor.
- Updated CommonCLI to handle new stats commands.
