Fix multi-pin power, add retries, remove refs to old data portal

[SRGDamia1]

Summary by CodeRabbit

• New Features

  • Added AWS IoT Core and S3 publishers for cloud data publishing.
  • Introduced Monitor My Watershed as primary data publishing platform (replaces EnviroDIY).
  • Enhanced sensor measurement retry logic and timing configuration.
  • Added support for external analog voltage readers across multiple sensors.
  • New processor analog sensing capabilities with unified interface.

• Bug Fixes

  • Improved sensor measurement validation and error handling.
  • Enhanced power management and wake-up sequences.
  • Better handling of invalid measurements and sensor responses.

• Documentation

  • Updated README and examples with new publisher references.
  • Added comprehensive developer setup guide.
  • Corrected terminology and fixed documentation typos.

• Breaking Changes

  • EnviroDIY publisher replaced with Monitor My Watershed publisher.
  • Various sensor constructor signatures updated for flexibility.
  • Removed data_saving example and related build configuration.