Handle drag and drop of Data dir

Also some general fixes to the data dir picker button.

lib/plugins.ts

@@ -0,0 +1,41 @@
+import { WorkerPool } from "./WorkerPool";
+import store from "./store";
+import { clearPlugins, setPending } from "../slices/plugins";
+
+export const excludedPlugins = [
+  "Skyrim.esm",
+  "Update.esm",
+  "Dawnguard.esm",
+  "HearthFires.esm",
+  "Dragonborn.esm",
+];
+
+export const isPluginPath = (path: string) => {
+  if (
+    path.endsWith(".esp") ||
+    path.endsWith(".esm") ||
+    path.endsWith(".esl")
+  ) {
+    return true;
+  }
+  return false;
+}
+
+export const isPlugin = (file: File) => {
+  return isPluginPath(file.name);
+}
+
+export const parsePluginFiles = (pluginFiles: File[], workerPool: WorkerPool) => {
+  store.dispatch(clearPlugins());
+  store.dispatch(setPending(pluginFiles.length));
+
+  pluginFiles.forEach(async (plugin) => {
+    const contents = new Uint8Array(await plugin.arrayBuffer());
+    workerPool.pushTask({
+      skipParsing: excludedPlugins.includes(plugin.name),
+      filename: plugin.name,
+      lastModified: plugin.lastModified,
+      contents,
+    });
+  });
+}