many fixes, add radioscope

• Added option to show/hide clock (with/without date)
• ADS-B RX app aircraft position jitter
• Radiosonde beep pitch RSSI improvements. Keeping current frequency in battery backed RAM
• fix save frequency gui glitch
• Adding radiosonde txt
• Feature radiosondes beep 371
• fix for freq manager save file
• fix in the scope of issue
• FrequencyStepView field to the TransmitterView class