Support other AWS partitions

[sre-ops]

I'm getting a token error on credentials that are known and working

[joshdk]

The various AWS partitions (aws, aws-us-gov, and aws-cn) are completely separate, and used different sts endpoints.

I would like aws-console to interoperate with all of these, but only the aws partition is currently supported. This is primarily due to only having an aws account to test with... 😁