Adding -debug flag to enable debugger-based debugging of the provider

[sandor-juhasz]

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

I tried running the provider in debug mode using Delve debugger and VSCode as described in the Terraform documentation (https://www.terraform.io/plugin/debugging#debugger-based-debugging) but the -debug command line flag is not supported by the current provider version.

Describe the solution you'd like

By adding the -debug command line flag, the provider binary should be able to start in debug mode and instructions on connecting to the provider should be printed to the end user. This mode is supported by the Terraform SDKv2 out of the box. The CLI parameter needs to be captured and passed to the SDK in the main.go file. See workflow details in the document linked above for the actual user experience.

Describe alternatives you've considered

No alternatives have been considered as this is the standard and expected behavior of providers.

Additional context

I have developed the fix for this missing feature and will submit the pull request shortly.