Move Value to helpers, separate span call (#10121)

# Description

As part of the refactor to split spans off of Value, this moves to using
helper functions to create values, and using `.span()` instead of
matching span out of Value directly.

Hoping to get a few more helping hands to finish this, as there are a
lot of commands to update :)

# User-Facing Changes
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---------

Co-authored-by: Darren Schroeder <343840+fdncred@users.noreply.github.com>
Co-authored-by: WindSoilder <windsoilder@outlook.com>

crates/nu-protocol/tests/test_pipeline_data.rs

@@ -4,21 +4,12 @@ use nu_protocol::{IntoPipelineData, Span, Value};
 fn test_convert_pipeline_data_to_value() {
     // Setup PipelineData
     let value_val = 10;
-    let value = Value::Int {
-        val: value_val,
-        span: Span::new(1, 3),
-    };
+    let value = Value::int(value_val, Span::new(1, 3));
     let pipeline_data = value.into_pipeline_data();
 
     // Test that conversion into Value is correct
     let new_span = Span::new(5, 6);
     let converted_value = pipeline_data.into_value(new_span);
 
-    assert_eq!(
-        converted_value,
-        Value::Int {
-            val: value_val,
-            span: new_span
-        }
-    );
+    assert_eq!(converted_value, Value::int(value_val, new_span));
 }

crates/nu-protocol/tests/test_value.rs

@@ -9,9 +9,7 @@ fn test_comparison_nothing() {
         Value::test_float(1.0),
     ];
 
-    let nothing = Value::Nothing {
-        span: Span::test_data(),
-    };
+    let nothing = Value::nothing(Span::test_data());
 
     for value in values {
         assert!(matches!(