PM-832 Multi storage

[piotr-iohk]

This pr adds ability to use many storage backends when running uptime service, i.e. one can configure AWS S3, AWS Keyspaces and Local filesystem at the same time or use any combination of the above (in particular AWS S3 and Keyspaces).

• This is tested by integration test that was modified to account for the change.
• Also manually tested behavior when the block exceeds 1MB. In such circumstance the block is saved on S3 and is not saved in Keyspaces with the following error message:

{"level":"warn",
"ts":"2023-12-12T12:23:32.825+0100",
"logger":"delegation backend",
"caller":"delegation_backend/aws_keyspaces.go:173",
"msg":"KeyspaceSave: Error saving block to Keyspaces: operation failed after 3 retries, returned error: The update would cause the row to exceed the maximum allowed size"}

For that the exponentialBackoff strategy was modified when inserting block/submission to keyspaces (3 retries, initial = 300ms, was: 10 retries , initial = 1s). I think new parameters better optimize for reasonable response time in case of transient issues still giving good error handling.

[Smorci]

Looks good to me!

[joaosreis]

LGTM! Just to double check, are those GPG files supposed to be included?

[piotr-iohk]

LGTM! Just to double check, are those GPG files supposed to be included?

Yes, they hold encoded config for integration test.