Fix warnings and split Scope (#1902)

crates/nu_plugin_str/src/nu/tests.rs

@@ -267,6 +267,7 @@ mod integration {
         Ok(())
     }
     #[test]
+    #[allow(clippy::approx_constant)]
     fn converts_the_input_to_float_using_the_field_passed_as_parameter() -> Result<(), ShellError> {
         let run = plugin(&mut Str::new())
             .args(

crates/nu_plugin_str/src/strutils.rs

@@ -294,6 +294,7 @@ pub mod tests {
     }
 
     #[test]
+    #[allow(clippy::approx_constant)]
     fn converts_to_float() -> Result<(), Box<dyn std::error::Error>> {
         let mut strutils = Str::new();
         strutils.for_to_float();