(core) Disabling unsaved changes when logging in

Summary:
Disabling unsaved changes when user tries to login or singup as those endpoints
tries to redirect back to the unsaved fork.

Test Plan: Added new test

Reviewers: georgegevoian

Reviewed By: georgegevoian

Subscribers: georgegevoian

Differential Revision: https://phab.getgrist.com/D4071

app/client/ui/AccountWidget.ts

@@ -60,6 +60,7 @@ export class AccountWidget extends Disposable {
     return [
       cssSigninButton(t('Sign In'),
         cssSigninButton.cls('-secondary'),
+        dom.on('click', () => { this._docPageModel?.clearUnsavedChanges(); }),
         dom.attr('href', use => {
           // Keep the redirect param of the login URL fresh.
           use(urlState().state);
@@ -68,6 +69,7 @@ export class AccountWidget extends Disposable {
         testId('user-sign-in'),
       ),
       cssSigninButton(t('Sign Up'),
+        dom.on('click', () => { this._docPageModel?.clearUnsavedChanges(); }),
         dom.attr('href', use => {
           // Keep the redirect param of the signup URL fresh.
           use(urlState().state);