### Summary
The output of `GET /api/v1/vaas` was not being correctly sorted. This pull request changes the behavior so that the output will be sorted by the `timestamp` field.
Additionally, duplicated code was removed in the VAA code that handles queries.
Also, there was an unused query parameter `sortBy` which was being exposed but not used. Hence it was removed.
Tracking issue: https://github.com/wormhole-foundation/wormhole-explorer/issues/233
### Summary
* On all endpoints, fix the behavior of the `page` parameter (which was previously being ignored).
* On `GET /api/v1/vaas`, fix the behavior of the `sortBy` parameter (which wasn't working when `parsedPayload=true`).
* For all endpoints, validate the query parameters `page`, `pageNumber` and `sortOrder`.
* Return descriptive errors when pagination-related parameters happen to be invalid (`page`, `pageSize`, `sortOrder`).
* Validate guardian addresses in query params.
### Testing plan
All parameters involved were manually tested.
* Adds api in go
* renames observation import in api
* Add signed_vaa endpoint [guardian api]
* Add governor endpoints to API
* fix devnet/api.yaml to up with a fixed port
Co-authored-by: Gabriel Zimmermann <gabrielemanuel@gmail.com>
agodnic
walker-16