Allow outputting `terraform-plugin-framework` types for documentation and LSP

### Use-cases

When Terraform outputs a provider schema, it only recognizes the built-in Terraform types, such as `String`, `Number`, `Bool` plus the collection types. The Terraform Plugin Framework overrides `Number` with `Int64` and `Float64` types, plus providers can add custom types.

The Terraform schema for `Int64` and `Float64` still reports `Number` in the schema. Custom provider types will also report the underlying built-in Terraform type.

### Proposal

Since Terraform is unaware of Terraform Plugin Framework and custom provider types, this cannot be resolved in Terraform schema. Consider adding a gRPC server that can return richer schema information that can be consumed by tooling such as [`terraform-plugin-docs`](https://github.com/hashicorp/terraform-plugin-docs) or [`terraform-ls`](https://github.com/hashicorp/terraform-ls)