Allow for s3 backend path style

[cloutierMat]

Motivation

Using tflocal as part of a docker-compose configuration requires to use path style for s3 bucket. While the provider configuration is enabling path style for buckets created by terraform, this configuration did not extend to s3 backend. As reported on issue #25 and in the Community Slack, use/force_path_style configuration was not respected

Changes

Set the default when overriding the backend to use path style. This decision came as this is also seems to be what is enabled by default when encountering s3 services. use_path_style has been in use since tf v1.6, prior version used force_path_style. There is a bit of a hacky way to switch. Maybe if more deprecation issue arise, a more elegant solution would be required to not turn this into spaghetti :smile:

Not In Scope

There are many other attributes not currently supported such as the mentioned encrypt and acl. Those changes might require a bit more testing with LocalStack and Terraform to make sure it stays compatible, so were left out of scope

Testing

No new test was introduced as the backend is already tested with legacy and latest Terraform cli. If I am missing a testing opportunity, I am all ears!