(core) Delete my account button

Summary:
Adding new "Delete my account" button to the profile page that allows users to remove completely
their accounts as long as they don't own any team site.

Test Plan: Added

Reviewers: georgegevoian, paulfitz

Reviewed By: georgegevoian, paulfitz

Subscribers: paulfitz

Differential Revision: https://phab.getgrist.com/D4037

app/gen-server/ApiServer.ts

@@ -177,7 +177,7 @@ export class ApiServer {
       return sendReply(req, res, query);
     }));
 
-    // // DELETE /api/orgs/:oid
+    // DELETE /api/orgs/:oid
     // Delete the specified org and all included workspaces and docs.
     this._app.delete('/api/orgs/:oid', expressWrap(async (req, res) => {
       const org = getOrgKey(req);

app/gen-server/lib/HomeDBManager.ts

@@ -837,7 +837,7 @@ export class HomeDBManager extends EventEmitter {
     }
     await this._connection.transaction(async manager => {
       const user = await manager.findOne(User, {where: {id: userIdToDelete},
-                                                relations: ["logins", "personalOrg"]});
+                                                relations: ["logins", "personalOrg", "prefs"]});
       if (!user) { throw new ApiError('user not found', 404); }
       if (name) {
         if (user.name !== name) {
@@ -853,6 +853,7 @@ export class HomeDBManager extends EventEmitter {
         .from('group_users')
         .where('user_id = :userId', {userId: userIdToDelete})
         .execute();
+
       await manager.delete(User, userIdToDelete);
     });
     return {