feat: Add support for authentication to the sdk, and plug it in the admin (#7349)

* feat: Add support for authentication to the sdk, and plug it in the admin

* fix: await fetch before returning in sdk

packages/core/js-sdk/src/auth/index.ts

@@ -0,0 +1,33 @@
+import { Client } from "../client"
+import { Config } from "../types"
+
+export class Auth {
+  private client: Client
+  private config: Config
+
+  constructor(client: Client, config: Config) {
+    this.client = client
+    this.config = config
+  }
+
+  login = async (payload: { email: string; password: string }) => {
+    // TODO: It is a bit strange to eg. require to pass `scope` in `login`, it might be better for us to have auth methods in both `admin` and `store` classes instead?
+    const { token } = await this.client.fetch<{ token: string }>(
+      "/auth/admin/emailpass",
+      {
+        method: "POST",
+        body: payload,
+      }
+    )
+
+    // By default we just set the token in memory, if configured to use sessions we convert it into session storage instead.
+    if (this.config?.auth?.type === "session") {
+      await this.client.fetch("/auth/session", {
+        method: "POST",
+        headers: { Authorization: `Bearer ${token}` },
+      })
+    } else {
+      this.client.setToken(token)
+    }
+  }
+}