Custom region support

[theogravity]

Is your feature request related to a problem? Please describe.

We use dynamodb local to work with dynamodb in our development cycle, and use a custom region of local to make sure we're really touching a local dynamo and not a remote one since local wouldn't be supported on an actual AWS dynamodb instance.

Describe the solution you'd like
Maybe a checkbox that enables a text box instead of the region dropdown to specify a custom region.

[thaerlabs]

@theogravity have you tried the Local tab when connecting? works for me

[theogravity]

That's the endpoint, though. dynamodb local will store internal tables by the region name