* [X7D] Various fixes
[Others]
- Fixes the Mixer / Inputs MOVE / COPY problem on X9E
- Adds the copy/paste/rename feature in SDCARD menu on X7D/SKY9X
- Merges some duplicated code using the new directory structure
- Cosmetics
* Rename EXT option to TELEMETRY
* Change test accordingly
* Rename FRSKY to TELEMETRY_FRSKY
* Rename ARDUPILOT to TELEMETRY_ARDUPILOT
* More renames (JETI, MAVLINK, NMEA)
* Fixes to make commit-test happy
* Further tests added to commit-test
* Cleanup
* Rename EXTSTD to TELEMETRY_NONE