Reorganize server files and address TODO comments

Changes:
- Remove unneeded dependencies from package.json
- Remove unneeded async build() methods from services
    - Use constructor as often as possible
- Rename and move storage services for clarity
    - creds.ts -> accounts.ts, and creds.json -> accounts.json
    - admin-config.ts -> admin-account.ts
    - vault.ts -> signing-keys.ts
- Rename ws.ts to websocket-server.ts for clarity and consistency
- Make WebSocketServer initialize using constructor and bind server upgrade to WebSocketServer.upgrade
- Remove unused send-account-message endpoint from account-router.ts
- Set issuer and audience claims for JWT
- Create new utils/jwt.ts file to remove code duplication for JWT signing and verifying
- Delete utils.ts and merge it with jami-swig.ts
- Handle potentially undefined types in jami-swig.ts
- Replace hard to read one-liners with functions in jami-swig.ts
- Rename types in jami-swig.ts for consistency with daemon
- Remove handled/answered TODO comments
- Remove TODO comment about using .env for jamid.node as it does not work for require()

GitLab: #87
Change-Id: I1e5216ffa79ea34dd7e9b61540fb7e37d1f66c9f
diff --git a/server/src/storage/admin-account.ts b/server/src/storage/admin-account.ts
new file mode 100644
index 0000000..b207cfd
--- /dev/null
+++ b/server/src/storage/admin-account.ts
@@ -0,0 +1,51 @@
+/*
+ * 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/>.
+ */
+import { readFileSync } from 'node:fs';
+import { writeFile } from 'node:fs/promises';
+
+import { Service } from 'typedi';
+
+@Service()
+export class AdminAccount {
+  private readonly filename = 'admin.json';
+  private account: { admin: string };
+
+  constructor() {
+    let buffer: Buffer;
+
+    try {
+      buffer = readFileSync(this.filename);
+    } catch (e) {
+      buffer = Buffer.from('{}');
+    }
+
+    this.account = JSON.parse(buffer.toString());
+  }
+
+  get(): string | undefined {
+    return this.account.admin;
+  }
+
+  set(password: string): void {
+    this.account.admin = password;
+  }
+
+  async save(): Promise<void> {
+    await writeFile(this.filename, JSON.stringify(this.account, null, 2) + '\n');
+  }
+}