feat: explicit provisioner outputs (#2725)

Removes the confusing generic string output property thing, and
explicitly states returned properties in the resources themselves.
Also, passes underlying platform parameters as config values to the
provisioning plugin for now. If we ever look at provisioning FTL
clusters themselves, we can rethink how to pass these properties to the
plugin.

This gives DB properties in a format like this:
```
{
  "resource_id": "foobardb",
  "Resource": {
    "Postgres": {
      "out_read_endpoint": "ftltest1-testmodule-foobardbcluster-4joq2vpkgsaz.cluster-ro-cr24kso0s7in.us-west-2.rds.amazonaws.com",
      "out_write_endpoint": "ftltest1-testmodule-foobardbcluster-4joq2vpkgsaz.cluster-cr24kso0s7in.us-west-2.rds.amazonaws.com"
    }
  }
}
```

After this, I am happy with the plugin API for now, and will start
looking at `ftl-provisioner` next.

backend/protos/xyz/block/ftl/v1beta1/provisioner/plugin.proto

@@ -8,6 +8,14 @@ import "xyz/block/ftl/v1beta1/provisioner/resource.proto";
 option go_package = "github.com/TBD54566975/ftl/backend/protos/xyz/block/ftl/v1beta1/provisioner;provisioner";
 option java_multiple_files = true;
 
+// ResourceContext is the context used to create a new resource
+// This includes the direct dependencies of the new resource, that can impact
+// the resource creation.
+message ResourceContext {
+  Resource resource = 1;
+  repeated Resource dependencies = 2;
+}
+
 message ProvisionRequest {
   string ftl_cluster_id = 1;
   string module = 2;
@@ -17,7 +25,7 @@ message ProvisionRequest {
 
   // The resource FTL would like to exist after this provisioning run.
   // This includes all new, existing, and changes resources in this change.
-  repeated Resource desired_resources = 4;
+  repeated ResourceContext desired_resources = 4;
 }
 
 message ProvisionResponse {
@@ -33,6 +41,11 @@ message ProvisionResponse {
 
 message StatusRequest {
   string provisioning_token = 1;
+
+  // The set of desired_resources used to initiate this provisioning request
+  // We need this as input here, so we can populate any resource fields in them
+  // when the provisioning finishes
+  repeated Resource desired_resources = 2;
 }
 
 message StatusResponse {
@@ -43,7 +56,9 @@ message StatusResponse {
   }
 
   message ProvisioningSuccess {
-    repeated ResourceProperty properties = 3;
+    // Some fields in the resources might have been populated
+    // during the provisioning. The new state is returned here
+    repeated Resource updated_resources = 1;
   }
 
   oneof status {