Support Minio STS AssumeRoleWithWebIdentity to obtain dynamic credentials

[matteo-s]

Description

Minio supports the STS api, enabling users possessing a valid oidc access_token (or id_token) to obtain a temporary set of credentials, which can then be used for regular S3 access.

The API expects a token as input, and returns a set of <AccessKeyId>,<SecretAccessKey>,<SessionToken>, valid until <Expiration>.

My proposal is to implement a new type of resource, called minio_sts_key which will support the Create action taking in input the required parameters and then enrich the resource with the newly obtained credentials.

Ref.
https://github.com/minio/minio/blob/master/docs/sts/web-identity.md

Additional Information

I can contribute a proof-of-concept implementation. See scc-digitalhub@1528ded