Misc JS linting and naming tweaks (#10652)

- lowercase all js filenames except Vue components
- enable new lint rules, mostly focused on shorter code
- autofix new lint violations
- apply misc transformations indexOf -> includes and onevent-> addEventListener

Co-authored-by: Antoine GIRARD <sapk@users.noreply.github.com>

web_src/js/features/gitgraph.js

@@ -0,0 +1,13 @@
+export default async function initGitGraph() {
+  const graphCanvas = document.getElementById('graph-canvas');
+  if (!graphCanvas) return;
+
+  const {default: gitGraph} = await import(/* webpackChunkName: "gitgraph" */'../vendor/gitgraph.js');
+
+  const graphList = [];
+  $('#graph-raw-list li span.node-relation').each(function () {
+    graphList.push($(this).text());
+  });
+
+  gitGraph(graphCanvas, graphList);
+}