fix: backport changes for html button in text component markdown editor (#2065)

Author: tonybusa

src/editors/sharedComponents/CodeEditor/hooks.js

@@ -100,7 +100,7 @@ export const createCodeMirrorDomNode = ({
 }) => {
   // eslint-disable-next-line react-hooks/rules-of-hooks
   useEffect(() => {
-    const languageExtension = CODEMIRROR_LANGUAGES[lang]();
+    const languageExtension = CODEMIRROR_LANGUAGES[lang] ? CODEMIRROR_LANGUAGES[lang]() : xml();
     const cleanText = cleanHTML({ initialText });
     const newState = EditorState.create({
       doc: cleanText,

src/editors/sharedComponents/SourceCodeModal/__snapshots__/index.test.jsx.snap

@@ -41,6 +41,7 @@ exports[`SourceCodeModal renders as expected with default behavior 1`] = `
   >
     <injectIntl(ShimmedIntlComponent)
       innerRef="moCKrEf"
+      lang="html"
       value="mOckHtMl"
     />
   </div>

src/editors/sharedComponents/SourceCodeModal/index.jsx

@@ -1,4 +1,3 @@
-import React from 'react';
 import PropTypes from 'prop-types';
 
 import {
@@ -41,6 +40,7 @@ const SourceCodeModal = ({
         <CodeEditor
           innerRef={ref}
           value={value}
+          lang="html" // hardcoded value to do lookup on CODEMIRROR_LANGUAGES
         />
       </div>
     </BaseModal>