* Add unknown guardian set index alert
* Add prometheus metrics to check if exists observations without txhash
* Add max sequence cache error prometheus metrics
### Summary
Before this PR, when validating a VAA, we were always using the latest guardian set index to verify the signatures.
With this PR, we're making the signature verification against `vaa.guardianSetIndex` instead.
Context: https://github.com/wormhole-foundation/wormhole-explorer/issues/104
### Testing plan
* Added unit test cases
* Also tested manually
* Add use of sequence cache in API
* Add sequence cache in fly
* Deploy for API
* Improve use cache in API
* Remove sequence cache in fly for pythnet
Co-authored-by: Fernando Torres <fert1335@gmail.com>
* Deduplication of vaas messages
Use persistent queue for vaas messages (except for pyth)
Add local flag for local execution (use a memory queue)
* Improve names for consumers
Add deduplication in memory for all vaas messages and tests
Split incoming vaas (pyth and non pyth) into different channels and tests
* Check if queue message is expired
* Code review updates
ftocal
walker-16
agodnic