Create service for resolving and parsing SecretTokens

# Feature Request

Right now, the same logic for resolving and parsing an `AwsSecretToken` or `AwsTemporarySecretToken` is duplicated multiple times (provisioning, data plane). It should be extracted to a new service (e.g. `SecretTokenResolver`), that is provided through the `s3-core` module and used by provisioning and data plane classes.

## Which Areas Would Be Affected?

s3-core, provisioning extensions, data plane extensions

## Why Is the Feature Desired?

maintainability

## Who will sponsor this feature?

me

## Solution Proposal

- create a service `SecretTokenResolver` which contains the logic for fetching a token from the vault and parsing it to the correct type of `SecretToken`, utilizing the `Vault` & the `TypeManager`
- provide this service as part of the `S3CoreExtension`
- use this service in all classes that need to use a `SecretToken`
- remove all duplications