Add -n flag to sort (formerly only available on sort-by) (#7293)

# Description

* `-n`, `--natural` flag from `sort-by` is now on the plain `sort`.
* The `-i`, `-n` and `-r` flags now work with single record sorting
(formerly they didn't)

# User-Facing Changes

See above.

# 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/tests/commands/mod.rs

@@ -75,6 +75,7 @@ mod semicolon;
 mod seq_char;
 mod shells;
 mod skip;
+mod sort;
 mod sort_by;
 mod source_env;
 mod split_by;

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

@@ -1,6 +1,5 @@
 use nu_test_support::{nu, pipeline};
 
-
 #[test]
 fn by_invalid_types() {
     let actual = nu!(
@@ -46,3 +45,76 @@ fn sort_different_types() {
     let json_output = r#"[1,2,3,4,"a","b","c","d",[1,2,3],[4,5,6]]"#;
     assert_eq!(actual.out, json_output);
 }
+
+#[test]
+fn sort_natural() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"['1' '2' '3' '4' '5' '10' '100'] | sort -n | to nuon"#
+    ));
+
+    assert_eq!(actual.out, r#"["1", "2", "3", "4", "5", "10", "100"]"#);
+}
+
+#[test]
+fn sort_record_natural() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{10:0,99:0,1:0,9:0,100:0} | sort -n | to nuon"#
+    ));
+
+    assert_eq!(
+        actual.out,
+        r#"{"1": 0, "9": 0, "10": 0, "99": 0, "100": 0}"#
+    );
+}
+
+#[test]
+fn sort_record_insensitive() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{abe:1,zed:2,ABE:3} | sort -i | to nuon"#
+    ));
+
+    assert_eq!(actual.out, r#"{abe: 1, ABE: 3, zed: 2}"#);
+}
+
+#[test]
+fn sort_record_insensitive_reverse() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{abe:1,zed:2,ABE:3} | sort -ir | to nuon"#
+    ));
+
+    assert_eq!(actual.out, r#"{zed: 2, ABE: 3, abe: 1}"#);
+}
+
+#[test]
+fn sort_record_values_natural() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{1:"1",2:"2",4:"100",3:"10"} | sort -vn | to nuon"#
+    ));
+
+    assert_eq!(actual.out, r#"{"1": "1", "2": "2", "3": "10", "4": "100"}"#);
+}
+
+#[test]
+fn sort_record_values_insensitive() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{1:abe,2:zed,3:ABE} | sort -vi | to nuon"#
+    ));
+
+    assert_eq!(actual.out, r#"{"1": abe, "3": ABE, "2": zed}"#);
+}
+
+#[test]
+fn sort_record_values_insensitive_reverse() {
+    let actual = nu!(
+        cwd: ".", pipeline(
+        r#"{1:abe,2:zed,3:ABE} | sort -vir | to nuon"#
+    ));
+
+    assert_eq!(actual.out, r#"{"2": zed, "3": ABE, "1": abe}"#);
+}