Update JS dependencies (#15033)

* Update JS dependencies

- Update all JS dependencies
- For octicons, rename trashcan to trash
- For svgo, migrate to v2 api, output seems to have slightly changed but icons look the same
- For stylelint, update config, fix custom property duplicates
- For monaco, drop legacy Edge support
- For eslint, enable new rules, fix new issues
- For less-loader, remove deprecated import syntax

* update svgo usage in generate-images and rebuild logo.svg with it

web_src/less/index.less

@@ -1,4 +1,4 @@
-@import "~font-awesome/css/font-awesome.css";
+@import "font-awesome/css/font-awesome.css";
 
 @import "./variables.less";
 @import "./shared/issuelist.less";