storage controller: use AWS Secrets Manager for database URL, etc (#6585)

## Problem

Passing secrets in via CLI/environment is awkward when using helm for
deployment, and not ideal for security (secrets may show up in ps,
/proc).

We can bypass these issues by simply connecting directly to the AWS
Secrets Manager service at runtime.

## Summary of changes

- Add dependency on aws-sdk-secretsmanager
- Update other aws dependencies to latest, to match transitive
dependency versions
- Add `Secrets` type in attachment service, using AWS SDK to load if
secrets are not provided on the command line.

libs/utils/src/auth.rs

@@ -127,6 +127,10 @@ impl JwtAuth {
         Ok(Self::new(decoding_keys))
     }
 
+    pub fn from_key(key: String) -> Result<Self> {
+        Ok(Self::new(vec![DecodingKey::from_ed_pem(key.as_bytes())?]))
+    }
+
     /// Attempt to decode the token with the internal decoding keys.
     ///
     /// The function tries the stored decoding keys in succession,