Update JS dependencies and misc tweaks (#13741)

* Update JS dependencies and misc tweaks

- Update all JS dependencies minus webpack
- Adapt CodeMirrors styling to new CSS parent introduced by EasyMDE
- Set eslint parser to latest and add new eslint 7.14 rule
- Speed up npm install by disabling audit and fund checks
- Move fomantic-ui to optional dependencies to further speed up npm
- Enable syntax highlighting on GH for .eslintrc and .stylelintrc
- Makefile cleanups

* disable audit in npmrc

* add missing dash

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

web_src/less/themes/theme-arc-green.less

@@ -1267,19 +1267,6 @@ a.blob-excerpt:hover {
 /* code mirror dark theme */
 
 .CodeMirror {
-  color: #9daccc;
-  background-color: #2e323e;
-  border-color: var(--color-secondary);
-  border-top: 0;
-
-  div.CodeMirror-cursor {
-    border-left: 1px solid var(--color-secondary-dark-6);
-  }
-
-  .CodeMirror-gutters {
-    background-color: #2e323e;
-  }
-
   &.cm-s-default,
   &.cm-s-paper {
     .cm-property {