[Feature] Upgrade Rudolph backend to support 2022-24 schema/sync changes

[radsec]

to: @MarkVLK @Tejunalwad
cc: @airbnb/rudolph-maintainers

Background

Its about time the sync server gets some TLC and upgrades...this PR is one of several in the coming days to perform some general housekeeping, upgrades, and cleanup of the overall codebase.

This PR is geared mainly at updating the backend and related TF infrastructure to support the latest sync-server schema changes since 2022 up to the latest 2024.2 sync schema.

The changes will be non-breaking and ensure backwards compatibility with legacy Santa agents.

Changes

• Update backend code to support 2022-2024.2 sync server schema changes
  • Incorporate the latest clean_sync types/behaviors --> Sync clean all google/santa#1275
  • Ensure backwards-compatibility for legacy Santa agents
• Updating related TF infrastructure to support sync server schema changes
• General housekeeping in updating the Golang version and its deps
  • Removal of legacy dependencies for better code security
  • Added additional unit testing code coverage

Testing

Virtual VM and tested the following:

• lockdown and monitor modes
• Published and tested a variety of sample rules which include blocks, silent_blocks,certificates, binaries, and bundle_rules
• Tested all sync-type behaviors with Rudolph

[natesinger]

LGTM