Reduced LOC by replacing several instances of Value::Int {}, Value::Float{}, Value::Bool {}, and Value::String {} with Value::int(), Value::float(), Value::boolean() and Value::string() (#7412)

# Description

While perusing Value.rs, I noticed the `Value::int()`, `Value::float()`,
`Value::boolean()` and `Value::string()` constructors, which seem
designed to make it easier to construct various Values, but which aren't
used often at all in the codebase. So, using a few find-replaces
regexes, I increased their usage. This reduces overall LOC because
structures like this:
```
Value::Int {
  val: a,
  span: head
}
```
are changed into
```
Value::int(a, head)
```
and are respected as such by the project's formatter.
There are little readability concerns because the second argument to all
of these is `span`, and it's almost always extremely obvious which is
the span at every callsite.

# User-Facing Changes

None.

# Tests + Formatting

Don't forget to add tests that cover your changes.

Make sure you've run and fixed any issues with these commands:

- `cargo fmt --all -- --check` to check standard code formatting (`cargo
fmt --all` applies these changes)
- `cargo clippy --workspace -- -D warnings -D clippy::unwrap_used -A
clippy::needless_collect` to check that you're using the standard code
style
- `cargo test --workspace` to check that all tests pass

# After Submitting

If your PR had any user-facing changes, update [the
documentation](https://github.com/nushell/nushell.github.io) after the
PR is merged, if necessary. This will help us keep the docs up to date.

crates/nu-command/src/strings/str_/substring.rs

@@ -134,10 +134,7 @@ fn action(input: &Value, args: &Arguments, head: Span) -> Value {
 
             if start < len && end >= 0 {
                 match start.cmp(&end) {
-                    Ordering::Equal => Value::String {
-                        val: "".to_string(),
-                        span: head,
-                    },
+                    Ordering::Equal => Value::string("", head),
                     Ordering::Greater => Value::Error {
                         error: ShellError::UnsupportedInput(
                             "End must be greater than or equal to Start".to_string(),
@@ -165,10 +162,7 @@ fn action(input: &Value, args: &Arguments, head: Span) -> Value {
                     },
                 }
             } else {
-                Value::String {
-                    val: "".to_string(),
-                    span: head,
-                }
+                Value::string("", head)
             }
         }
         other => Value::Error {
@@ -304,10 +298,7 @@ mod tests {
 
     #[test]
     fn substrings_indexes() {
-        let word = Value::String {
-            val: "andres".to_string(),
-            span: Span::test_data(),
-        };
+        let word = Value::string("andres", Span::test_data());
 
         let cases = vec![
             expectation("a", (0, 1)),
@@ -346,13 +337,7 @@ mod tests {
                 Span::test_data(),
             );
 
-            assert_eq!(
-                actual,
-                Value::String {
-                    val: expected.to_string(),
-                    span: Span::test_data()
-                }
-            );
+            assert_eq!(actual, Value::string(expected, Span::test_data()));
         }
     }
 }