fix: Disable URL rewriting when creating links

The default behavior of the TinyMCE editor is to rewrite links that share the same
domain as the component to be relative to that path. Relative URLs will never work in
email contents, so they _always_ need to be absolute URLs. This adds the configuration
settings for `relative_urls` and `remove_script_host` in TinyMCE to always be false,
enabling it to always use absolute URLs. See
[here](https://www.tiny.cloud/docs/configure/url-handling/) for reference.

src/components/bulk-email-tool/text-editor/TextEditor.jsx

@@ -43,6 +43,8 @@ export default function TextEditor(props) {
         block_unsupported_drop: false,
         image_advtab: true,
         name: 'emailBody',
+        relative_urls: false,
+        remove_script_host: false,
       }}
       onEditorChange={onChange}
       value={value}