WIP(tfgrid3deployer): Support deploying on hetzner nodes

- Add support for deploying VMs, ZDBs, and gateways on Hetzner nodes.
- Introduce `use_hetzner_node` flag to VM, ZDB, and WebName.
- Update `filter_nodes` to filter by Hetzner farm IDs if `on_hetzner` flag is set.
- Implement `get_hetzner_farm_ids` function (currently a placeholder).

Co-authored-by: mahmmoud.hassanein <mahmmoud.hassanein@gmail.com>

lib/threefold/tfgrid3deployer/webnames.v

@@ -8,9 +8,9 @@ pub mut:
 	name                  string @[required]
 	node_id               ?u32
 	use_wireguard_network bool
+	use_hetzner_node      bool
 	// must be in the format ip:port if tls_passthrough is set, otherwise the format should be http://ip[:port]
 	backend         string @[required]
-	use_wireguard   bool
 	tls_passthrough bool
 }