tests: bluetooth: tester: Add Upload OOB support for mesh tester

This allow to run the following PTS test:
- DFU/SR/FD/BV-06-C
- DFU/SR/FD/BV-13-C
- DFU/SR/FD/BV-14-C
- DFU/SR/FD/BV-15-C
- DFU/SR/FD/BV-16-C
- DFU/SR/FD/BV-17-C
- DFU/SR/FD/BV-18-C
- DFU/SR/FD/BV-22-C

Signed-off-by: Pavel Vasilyev <pavel.vasilyev@nordicsemi.no>