Fix provider attribute to block conversion

[dbanck]

To mimic Terraform's built-in backwards-compatible logic, where list(object) or set(object) attributes are also accessible as blocks, we check all attributes to see if they match those types. But we only did this for the top-level attributes of a block, and didn't check nested attributes. This PR fixes that.

The example in hashicorp/vscode-terraform#1594 had three attributes, that were also available as a block: managed_disk, network_interface, and unmanaged_disk. All three are of type set(object) and encoded as such in the provider schema.

We convert them to blocks in

terraform-schema/schema/convert_json.go

Lines 123 to 134 in 8c97616

	func convertibleAttributesToBlocks(attributes map[string]*tfjson.SchemaAttribute) map[string]*schema.BlockSchema {
	blocks := make(map[string]*schema.BlockSchema, 0)
	for name, attr := range attributes {
	if typeCanBeBlocks(attr.AttributeType) {
	blockSchema, ok := blockSchemaForAttribute(attr)
	if !ok {
	continue
	}
	blocks[name] = blockSchema
	}
	}

and so they show up for completion in the top-level dynamic block

managed_disk contains the attribute target_disk_encryption with type list(object) that also could be a block, but we never tried to convert it. So it never showed up for completion in a nested dynamic block and was marked as a problem by the schema validation.

UX

Before

After

---

• Resolves Incorrectly flagging nested dynamic blocks as errors vscode-terraform#1594

[radeksimko]

LGTM, thanks for the fix and the test as well.