Process widget data in background when widgets are closed

[retiutut]

Networking Outputs, and those that need data processed in the background:

• [x] Time Series filtered - Done
• [x] Time Series unfiltered - Done
• [x] Focus - NEED
• [x] FFT - Done
• [x] EMG - Done
• [x] AvgBandPower - NEED
• [x] BandPower - Done
• [x] Accelerometer - NEED
• [x] Digital Read - NEED
• [x] Analog Read - NEED
• [x] Pulse - NEED
• [x] EMG Joystick - NEED
• [x] Marker - Done
• [x] Process sampling rate dependent data accumulation in background when Networking widget is closed

[philippitts]

Tested and confirmed the changes are working as expected 👍

[retiutut]

Closes #1094