feat(pgp): add piece to decrypt pgp file

[tpujolalan]

What does this PR do?

Create a new action getting a file from an AWS S3 bucket and decrypt this file using AWS Secrets manager to retrieve the private key.

Explain How the Feature Works

• Use a connection to AWS
• Take private key & secret ARNs
• Get the given S3 file from its path
• Retrieve private key & secret from AWS Secrets manager
• Decrypt the encrypted file given by the flow
• Returns a decrypted file to be used in the flow

Relevant User Scenarios

• An encrypted file is stored in S3
• It needs to be decrypted to be treated

[AdamSelene]

Some minor comments + bump the package version (mandatory)