fix: Show degree symbol `°` instead of `@`

[pfeerick]

For temperature and degree units, @C, @F and @ were being shown, rather than °C, °F and °.

It seems B&W show the ° symbol when @ is used.

Also, some translations were missing dBm as a telemetry unit.

as opposed to

Also hoping this will also resolve the GPS sensor showing @ instead of ° as mentioned in #2163.