refactor(editor): Replace monaco-editor/prismjs with CodeMirror (#5983)

Co-authored-by: Jan Oberhauser <jan.oberhauser@gmail.com>
Co-authored-by: Milorad FIlipović <milorad@n8n.io>
Co-authored-by: Alex Grozav <alex@grozav.com>

packages/design-system/src/css/_tokens.dark.scss

@@ -276,6 +276,7 @@
 	--color-json-highlight: #dcdfea;
 
 	--color-code-background: #222020;
+	--color-code-background-readonly: #323230;
 	--color-code-foreground: #f8f8f2;
 	--color-code-caret: #f8f8f0;
 	--color-code-selection: #312b25;