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-parser/src/parser.rs

@@ -5147,6 +5147,8 @@ pub fn parse_operator(working_set: &mut StateWorkingSet, span: Span) -> Expressi
         b"//" => Operator::Math(Math::FloorDivision),
         b"in" => Operator::Comparison(Comparison::In),
         b"not-in" => Operator::Comparison(Comparison::NotIn),
+        b"has" => Operator::Comparison(Comparison::Has),
+        b"not-has" => Operator::Comparison(Comparison::NotHas),
         b"mod" => Operator::Math(Math::Modulo),
         b"bit-or" => Operator::Bits(Bits::BitOr),
         b"bit-xor" => Operator::Bits(Bits::BitXor),
@@ -5187,7 +5189,7 @@ pub fn parse_operator(working_set: &mut StateWorkingSet, span: Span) -> Expressi
         b"contains" => {
             working_set.error(ParseError::UnknownOperator(
                 "contains",
-                "Did you mean '$string =~ $pattern' or '$element in $container'?",
+                "Did you mean 'has'?",
                 span,
             ));
             return garbage(working_set, span);