(core) move home server into core

Summary: This moves enough server material into core to run a home server.  The data engine is not yet incorporated (though in manual testing it works when ported).

Test Plan: existing tests pass

Reviewers: dsagal

Reviewed By: dsagal

Differential Revision: https://phab.getgrist.com/D2552

app/common/GristServerAPI.ts

@@ -0,0 +1,84 @@
+import {BasketClientAPI} from 'app/common/BasketClientAPI';
+import {DocListAPI} from 'app/common/DocListAPI';
+import {LoginSessionAPI} from 'app/common/LoginSessionAPI';
+import {EmailResult, Invite} from 'app/common/sharing';
+import {UserConfig} from 'app/common/UserConfig';
+
+export interface GristServerAPI extends
+  DocListAPI,
+  LoginSessionAPI,
+  BasketClientAPI,
+  ServerMetricsAPI,
+  UserAPI,
+  SharingAPI,
+  MiscAPI {}
+
+
+interface ServerMetricsAPI {
+  /**
+   * Registers the list of client metric names. The calls to pushClientMetrics() send metric
+   * values as an array parallel to this list of names.
+   */
+  registerClientMetrics(clientMetricsList: string[]): Promise<void>;
+
+  /**
+   * Sends bucketed client metric data to the server. The .values arrays contain one value for
+   * each of the registered metric names, as a parallel array.
+   */
+  pushClientMetrics(clientBuckets: Array<{startTime: number, values: number[]}>): Promise<void>;
+}
+
+interface UserAPI {
+  /**
+   * Gets the Grist configuration from the server.
+   */
+  getConfig(): Promise<UserConfig>;
+
+  /**
+   * Updates the user configuration and saves it to the server.
+   * @param {Object} config - Configuration object to save.
+   * @returns {Promise:Object} Configuration object as persisted by the server. You can use it to
+   * validate the configuration.
+   */
+  updateConfig(config: UserConfig): Promise<UserConfig>;
+
+  /**
+   * Re-load plugins.
+   */
+  reloadPlugins(): Promise<void>;
+}
+
+interface SharingAPI {
+  /**
+   * Looks up a user account by email, return an object with basic user profile information.
+   */
+  lookupEmail(email: string): Promise<EmailResult|null>;
+
+  /**
+   * Fetches and saves invites from the hub which are not already present locally.
+   * Returns the new invites from the hub only.
+   */
+  getNewInvites(): Promise<Invite[]>;
+
+  /**
+   * Fetches local invites and marks them all as read.
+   */
+  getLocalInvites(): Promise<Invite[]>;
+
+  /**
+   * Marks the stored local invite belonging to the calling instance as ignored.
+   * Called when the user declines an invite.
+   */
+  ignoreLocalInvite(docId: string): Promise<void>;
+
+  /**
+   * Downloads a shared doc by creating a new doc and applying the snapshot actions associated
+   * with the given docId on the sharing hub. Must be called from a logged in account and instance
+   * invited to download the doc. Returns the actual non-conflicting docName used.
+   */
+  downloadSharedDoc(docId: string, docName: string): Promise<string>;
+}
+
+interface MiscAPI {
+  showItemInFolder(docName: string): Promise<void>;
+}