Object storage updates

[scross01]

• Adds metadata block to opc_storage_container for custom meta data headers
• Adds metadata block to opc_storage_object for custom meta data headers
• Adds quota_bytes and quota_count attributes to opc_storage_container
• Fixed and updated docs for opc_storage_container and opc_storage_object

[mbfrahry]

We'll have to cut a new release for the sdk and get those changes over here. Also, since these are PaaS changes, how would you feel about holding off on these changes until we make the new PaaS provider?

[scross01]

Object Storage is considered an Infrastructure service, not PaaS, so would stay as part of the opc provider. Not sure why it had been labeled PaaS before, I fixed the reference in the docs.

[mbfrahry]

Oh! That's really good to hear. I was worried we'd have to do some shenanigans to get it into the PaaS provider but this makes the path forward a lot easier.

[mbfrahry]

I've updated this PR with the latest version of the sdk if you want to take a crack at finishing it up

[mbfrahry]

LGTM