Remove dfr from dataframe commands (#5760)

* input and output tests

* input and output types for dfr

* expression converter

* remove deprecated command

* correct expressions

* cargo clippy

* identifier for ls

* cargo clippy

* type for head and tail expression

* modify full cell path if block

crates/nu-command/src/default_context.rs

@@ -400,9 +400,6 @@ pub fn create_default_context(cwd: impl AsRef<Path>) -> EngineState {
             KeepWhileDeprecated,
         };
 
-        #[cfg(feature = "dataframe")]
-        bind_command!(DataframeDeprecated);
-
         #[cfg(feature = "plugin")]
         bind_command!(Register);