Reorganize frontend files and tooling (#10168)

- move "vendor" files to js/vendor and less/vendor
- move swagger to js/standalone (meant for standalone pages)
- move gitgraph to features and streamline its loading
- add linting configs to webpack dependencies in make
- set ignored files for eslint/stylelint directly in their configs

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: zeripath <art27@cantab.net>
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);
+}