Implement a storage service to upload contracts on S3

[marcocastignoli]

This PR implements an S3-based storage service. The service allows uploading verified contract files to an S3 bucket while maintaining the same directory structure as RepositoryV2.

• Added new S3RepositoryService class that implements the storage interface
• Added S3 configuration options in .env.dev
• Integrated AWS SDK for S3 operations
• Added S3 storage service initialization in the server setup

S3RepositoryService is an extension of RepositoryV2, in which the write/delete/get file functions are overridden: instead of editing a fs, it's calling the AWS SDK APIs.

TODO:

• Clean code
• Add tests

[kuzdogan]

Haven't looked yet but IMO we should name it to S3Repository instead of RepositoryS3 it looks too similar toRepositoryV3

[marcocastignoli]

Haven't looked yet but IMO we should name it to S3Repository instead of RepositoryS3 it looks too similar toRepositoryV3

I already called it like this in the code but forgot to update the description, I had the same thought yesterday :D

[manuelwedler]

Great solution to our problem with the s3 sync script :)

I only have a few minor comments.

[manuelwedler]

Thanks!