Plugin architecture (#4861)

* wip

* Refactor, tasks, processors, routes loading

* Move Slack settings config to plugin

* Fix translations in plugins

* Move Slack auth to plugin

* test

* Move other slack-related files into plugin

* Forgot to save

* refactor

plugins/slack/client/components/SlackButton.tsx

@@ -0,0 +1,38 @@
+import * as React from "react";
+import { useTranslation } from "react-i18next";
+import { slackAuth } from "@shared/utils/urlHelpers";
+import Button from "~/components/Button";
+import env from "~/env";
+
+type Props = {
+  scopes?: string[];
+  redirectUri: string;
+  icon?: React.ReactNode;
+  state?: string;
+  label?: string;
+};
+
+function SlackButton({ state = "", scopes, redirectUri, label, icon }: Props) {
+  const { t } = useTranslation();
+
+  const handleClick = () => {
+    if (!env.SLACK_CLIENT_ID) {
+      return;
+    }
+
+    window.location.href = slackAuth(
+      state,
+      scopes,
+      env.SLACK_CLIENT_ID,
+      redirectUri
+    );
+  };
+
+  return (
+    <Button onClick={handleClick} icon={icon} neutral>
+      {label || t("Add to Slack")}
+    </Button>
+  );
+}
+
+export default SlackButton;