Add new operators has and not-has (#14841)

# Description
This PR add 2 new operators, `has` and `not-has`. They are basically
`in` and `not-in` with the order of operands swapped.

Motivation for this was the awkward way of searching for rows that
contain an item using `where`

```nushell
[[name, children]; [foo, [a, b, c]], [bar [d, e, f]]]
| where ("e" in $it.children)
```
vs
```nushell
[[name, children]; [foo, [a, b, c]], [bar [d, e, f]]]
| where children has "e"
``` 

# User-Facing Changes
Added `has` and `not-has` operators, mirroring `in` and `not-in`.

# Tests + Formatting

- 🟢 toolkit fmt
- 🟢 toolkit clippy
- 🟢 toolkit test
- 🟢 toolkit test stdlib

# After Submitting

crates/nu-command/src/help/help_operators.rs

@@ -141,6 +141,12 @@ fn description(operator: &Operator) -> &'static str {
         Operator::Comparison(Comparison::NotIn) => {
             "Checks if a value is not in a list, is not part of a string, or is not a key in a record."
         }
+        Operator::Comparison(Comparison::Has) => {
+            "Checks if a list contains a value, a string contains another, or if a record has a key."
+        }
+        Operator::Comparison(Comparison::NotHas) => {
+            "Checks if a list does not contain a value, a string does not contain another, or if a record does not have a key."
+        }
         Operator::Comparison(Comparison::StartsWith) => "Checks if a string starts with another.",
         Operator::Comparison(Comparison::EndsWith) => "Checks if a string ends with another.",
         Operator::Math(Math::Plus) => "Adds two values.",

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

@@ -187,3 +187,25 @@ fn where_gt_null() {
     let actual = nu!("[{foo: 123} {}] | where foo? > 10 | to nuon");
     assert_eq!(actual.out, "[[foo]; [123]]");
 }
+
+#[test]
+fn has_operator() {
+    let actual = nu!(
+        r#"[[name, children]; [foo, [a, b]], [bar [b, c]], [baz, [c, d]]] | where children has "a" | to nuon"#
+    );
+    assert_eq!(actual.out, r#"[[name, children]; [foo, [a, b]]]"#);
+
+    let actual = nu!(
+        r#"[[name, children]; [foo, [a, b]], [bar [b, c]], [baz, [c, d]]] | where children not-has "a" | to nuon"#
+    );
+    assert_eq!(
+        actual.out,
+        r#"[[name, children]; [bar, [b, c]], [baz, [c, d]]]"#
+    );
+
+    let actual = nu!(r#"{foo: 1} has foo"#);
+    assert_eq!(actual.out, "true");
+
+    let actual = nu!(r#"{foo: 1} has bar "#);
+    assert_eq!(actual.out, "false");
+}