[FEAT] ir_attachment_s3: Added support for Minio

[mlaitinen]

This modification allows to use Minio open source storage server as the attachment store instead of Amazon S3.

[yelizariev]

I missed that, sorry.
About the update, we thought to make separate modules for different types of storage, so it's supposed to be ir_attachment_minio module.
I understand, that it's too much to ask you to refactor your update. We might do it ourselves at some point, but I cannot say when

[mlaitinen]

I'm actually using another module for this already, so I'm going to close this MR. Feel free to use any of the code in this MR if you will create a ir_attachment_minio module.