Integrate new server authentication to client

Changes:
- Use server authentication REST API
- Log in automatically after registration
- Store token in localStorage
- Give feedback to user if registration or login fails

GitLab: #75
Change-Id: Ib90e5b911621567c6825af5e275920d703cdfe88
diff --git a/client/src/utils/errors.ts b/client/src/utils/errors.ts
new file mode 100644
index 0000000..30ec7aa
--- /dev/null
+++ b/client/src/utils/errors.ts
@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2022 Savoir-faire Linux Inc.
+ *
+ * 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
+ * <https://www.gnu.org/licenses/>.
+ */
+export class UsernameNotFound extends Error {}
+
+export class InvalidPassword extends Error {}