Draft: Rewrite update-binary script to support A/B and dynamic partitioning

Loosely based on update-binary from MindTheGapps

How to test:

1. Download the latest OTA Zip.
2. Download the modified update-binary (direct download link).
3. Inside the Zip, replace META-INF/com/google/android/update-binary with the modified version.
   • You may need to manually extract, modify, and re-compress the Zip archive depending on what software you use. Make sure to maintain the same directory structure as the original Zip.
4. Flash the modified Zip in recovery mode as normal.

Current status (based on limited testing):

• Works with A/B-partitioning
• Works with dynamic partitions
• Fails with certain non-A/B devices (old script worked)

TODO:

• Better logging
• If possible, verify successful installation and fall back on old method
• Investigate issues with known-failing devices

Supersedes: !65 (closed), !61, !54 (closed)
Should resolve: #81 (main issue thread), #79, #75, #73, #71, #69, #64, #62