Add support for listener-operator (#143)

## Description

*Please add a description here. This will become the commit message of the merge request later.*

Author: nightkr

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Added
+
+- Added Listener operator to supported operators ([#143](https://github.com/stackabletech/stackablectl/pull/143))
+
 ## [0.5.0] - 2022-09-14
 
 ### Added

src/main.rs

@@ -24,6 +24,7 @@ const AVAILABLE_OPERATORS: &[&str] = &[
     "hdfs",
     "hive",
     "kafka",
+    "listener",
     "nifi",
     "opa",
     "secret",

src/operator.rs

@@ -281,7 +281,7 @@ impl Operator {
     pub fn new(name: String, version: Option<String>) -> Result<Self, String> {
         if !AVAILABLE_OPERATORS.contains(&name.as_str()) {
             Err(format!(
-                "The operator {name} does not exist or stackablectl is to old to know the operator"
+                "The operator {name} does not exist or stackablectl is too old to know the operator"
             ))
         } else {
             Ok(Operator { name, version })