[WEB-2414] chore: remove modal for creating a page

[aaryan610]

Improvements:

Now, clicking on the Add page button doesn't open a modal, instead it directly creates a new untitled page and redirects the user to it.

Pressing the shortcut D still opens up the create page modal.

Media:

https://github.com/user-attachments/assets/0bb90700-8447-4d7c-b50a-e0f054c3d728

Plane issue: WEB-2414

Summary by CodeRabbit

• New Features

  • Enhanced page creation process with direct button interaction and loading feedback.
  • Added automatic focus to the title input field in the page editor for improved usability.

• Bug Fixes

  • Improved error handling during page creation to provide user notifications.