Set Terraform Cloud Workspace execution mode in account request

[wellsiau-aws]

Describe the outcome you'd like

As a AFT user, I want to run Terraform Cloud using Terraform Cloud agent, so my Terraform workflow runs in private environment. Ref https://www.terraform.io/cloud-docs/workspaces/settings#execution-mode

Is your feature request related to a problem you are currently experiencing? If so, please describe.

At the moment AFT creates TFC workspace with default value for data.attributes.execution-mode (default to remote). Ref: https://www.terraform.io/cloud-docs/api-docs/workspaces

As user, I have to manually change it after the workspace is created.

Additional context

During account request, I will specify two item:

1. data.attributes.execution-mode to specify execution mode
2. data.attributes.agent-pool-id to specify which agent pool to use

[balltrev]

Thanks for the feature request @wellsiau-aws , I've gone ahead and made a backlog to add this functionality to AFT