[chore] Convert some settings / admin panel JS to TypeScript (#2247)

* initial conversion of STUFF to typescript

* more stuff

* update babel deps, include commonjs transform

* update bundler & eslint configuration

* eslint --fix

* upgrade deps

* update docs, build stuff, peripheral stuff

---------

Co-authored-by: f0x <f0x@cthu.lu>

web/source/settings/redux/oauth.ts

@@ -0,0 +1,89 @@
+/*
+	GoToSocial
+	Copyright (C) GoToSocial Authors admin@gotosocial.org
+	SPDX-License-Identifier: AGPL-3.0-or-later
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU Affero General Public License as published by
+	the Free Software Foundation, either version 3 of the License, or
+	(at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU Affero General Public License for more details.
+
+	You should have received a copy of the GNU Affero General Public License
+	along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+import { PayloadAction, createSlice } from "@reduxjs/toolkit";
+
+/**
+ * OAuthToken represents a response
+ * to an OAuth token request.
+ */
+export interface OAuthToken {
+	/**
+	 * Most likely to be 'Bearer'
+	 * but may be something else.
+	 */
+	token_type: string;
+	/**
+	 * The actual token. Can be passed in to
+	 * authenticate further requests using the
+	 * Authorization header and the token type.
+	 */
+	access_token: string;
+}
+
+export interface OAuthApp {
+	client_id: string;
+	client_secret: string;
+}
+
+export interface OAuthState {
+	instanceUrl?: string;
+	loginState: "none" | "callback" | "login" | "logout";
+	expectingRedirect: boolean;
+	/**
+	 * Token stored in easy-to-use format.
+	 * Will look something like:
+	 * "Authorization: Bearer BLAHBLAHBLAH"
+	 */
+	token?: string;
+	app?: OAuthApp;
+}
+
+const initialState: OAuthState = {
+	loginState: 'none',
+	expectingRedirect: false,
+};
+
+export const oauthSlice = createSlice({
+	name: "oauth",
+	initialState: initialState,
+	reducers: {
+		authorize: (_state, action: PayloadAction<OAuthState>) => {
+			// Overrides state with payload.
+			return action.payload;
+		},
+		setToken: (state, action: PayloadAction<OAuthToken>) => {
+			// Mark us as logged in by storing token.
+			state.token = `${action.payload.token_type} ${action.payload.access_token}`;
+			state.loginState = "login";
+		},
+		remove: (state) => {
+			// Mark us as logged out by clearing auth.
+			delete state.token;
+			delete state.app;
+			state.loginState = "logout";
+		}
+	}
+});
+
+export const {
+	authorize,
+	setToken,
+	remove,
+} = oauthSlice.actions;