ConvertValue creates a new attr.Value of the attr.Type `typ`, using the data in `val`, which can be of any attr.Type so long as its TerraformType method returns a tftypes.Type that `typ`'s ValueFromTerraform method can accept.

ValueAs takes the attr.Value `val` and populates the Go value `target` with its content.

ValueFrom takes the Go value `val` and populates `target` with an attr.Value, based on the type definition provided in `targetType`.

Config represents a Terraform config.

Plan represents a Terraform plan.

State represents a Terraform state.