Implement chunk_by operation (#14410)

# Description

This pull requests implements a new ~~partition-by~~ `chunk-by` command.
The operation takes a closure and partitions the input list into
sublists based on the return value of the closure.
- fixes #14149

Examples, tests and and documentation were added accordingly.


![image](https://github.com/user-attachments/assets/c272e2ec-9af3-4a88-832b-ddca4eb14c8f)


![image](https://github.com/user-attachments/assets/178968e7-c165-4d8c-858c-98584d653b0a)

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

@@ -0,0 +1,58 @@
+use nu_test_support::{nu, pipeline};
+
+#[test]
+fn chunk_by_on_empty_input_returns_empty_list() {
+    let actual = nu!("[] | chunk-by {|it| $it} | to nuon");
+    assert!(actual.err.is_empty());
+    assert_eq!(actual.out, "[]");
+}
+
+#[test]
+fn chunk_by_strings_works() {
+    let sample = r#"
+                [a a a b b b c c c a a a]
+            "#;
+
+    let actual = nu!(pipeline(&format!(
+        r#"
+                {sample}
+                | chunk-by {{|it| $it}}
+                | to nuon
+            "#
+    )));
+
+    assert_eq!(actual.out, "[[a, a, a], [b, b, b], [c, c, c], [a, a, a]]");
+}
+
+#[test]
+fn chunk_by_field_works() {
+    let sample = r#"[
+    {
+        name: bob,
+        age: 20,
+        cool: false
+    },
+    {
+        name: jane,
+        age: 30,
+        cool: false
+    },
+    {
+        name: marie,
+        age: 19,
+        cool: true
+    },
+    {
+        name: carl,
+        age: 36,
+        cool: true
+    } ]"#;
+
+    let actual = nu!(pipeline(&format!(
+        r#"{sample}
+           | chunk-by {{|it| $it.cool}}
+           | length"#
+    )));
+
+    assert_eq!(actual.out, "2");
+}