Extract raw shell/bash scripts as actual shell script files (#751)

### Description of the change

This is a preparation for #724 (bash script testing) which would be too complex to review if done there. I haven't changed the script contents.

### Benefits

Better IDE support, possibility for shell checks, tests.

### Possible drawbacks

-

### Additional information

I only extracted files that are native bash scripts. There are others, being a mix of Helm templating and shell scripts. Those scripts must be cleared first before extracting them as well.

Reviewed-on: https://gitea.com/gitea/helm-chart/pulls/751
Co-authored-by: justusbunsi <sk.bunsenbrenner@gmail.com>
Co-committed-by: justusbunsi <sk.bunsenbrenner@gmail.com>

.vscode/settings.json

@@ -4,5 +4,9 @@
             "/unittests/**/*.yaml"
         ]
     },
-    "yaml.schemaStore.enable": true
+    "yaml.schemaStore.enable": true,
+    "[shellscript]": {
+        "files.eol": "\n",
+        "editor.tabSize": 2
+    }
 }