audioreactive update (align with MoonMod code)

[softhack007]

This update provides bug fixing & minor improvements for audioreactive usermod. It is based on the "MoonMod" version, but leaves out a few experimental features, like mic profiles and experimental "I2S slave mode" support.

@blazoncek would be nice if you can do a quick code review before we merge this PR.

Changes to audio drivers:

• small improvements for analog input driver
• Better handling of PDM and Line-In
• Bugfixes for ES7243 (allocateMultiplePins() needed for I2C part)
• More error messages for ES7243
• sample scaling (needed for sources that provide full scale (16bit) samples)

Changes in audiorective usermod core:

• align SR_DEBUG with WLED_DEBUG
• optional bandpass filter (needed for PDM mics)
• sample scaling for PDM and Line-In
• small improvements for analog input
• bugfixes and small performance improvements
• code for FFT task refactored, for better readablity. Introduces separate functions for filtering and post-processing
• small improvement for beat detection
• default mic settings can be configured at compile time
• correct mic type if MCU does not support PDM or ADC
• hide analog PIN config if not supported by MCU

[softhack007]

Hi @blazoncek, please cross-check my changes to the readme.md. If OK for you, please hit "merge" ;-)

[softhack007]

I'm merging this now, before source codes start to diverge.. @blazoncek please feel free to modify the usermod readme.md in case you want something changed/added.