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.",