Add/update instance and VPC retry on create/delete actions

[optik-aper]

Description

• Add a retry to resource instance create
• Update the retry on VPC delete to use the correct timeout
• Adjust some of the VPC variables for better readability

Related Issues

Closes #322

Checklist:

• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Have you linted your code locally prior to submission?
• Have you successfully ran tests with your changes locally?

[optik-aper]

The VPC delete retry will cause a timeout to occur if the VPC is removed when still attached to resources. There's no easy way to determine what is attached to a VPC right now so that we can do the removal in order. That should change with VPC 2.0, so, see issue #363

[mondragonfx]

Looks good. Approved.