Validate upload size against the node limit before uploading

Expose the node's upload_size on the client server resource and reject
files over it in the file manager before any bytes are sent.

resources/scripts/api/generated/types.gen.ts

@@ -1364,6 +1364,7 @@ export type ClientServerAttributes = {
     name: string;
     node: string;
     is_node_under_maintenance: boolean;
+    upload_size: number;
     sftp_details: {
         ip: string;
         port: number;