Introduce new command - nu check (#5864)

* nu check command - 1

* Support stream

* Polish code and fix corner case

crates/nu-command/tests/commands/mod.rs

@@ -38,6 +38,7 @@ mod merge;
 mod mkdir;
 mod move_;
 mod network;
+mod nu_check;
 mod open;
 mod parse;
 mod path;