[18.0][ADD] document_page_project_task: add new module

[CristianoMafraJunior]

SuperSeed #564

This module extends the document page (wiki) functionality by allowing you to link them directly to project tasks.

Main Features

• Link Wiki Pages to Tasks: Allows associating document pages to specific project tasks
• Automatic Project Filling: When a task is selected, the related project is automatically filled
• Consistency Validation: Ensures that the wiki page's project is always the same as the linked task's project
• Smart Filtering: When a project is defined, only tasks from that project are displayed for selection
• Page Counter: Displays the number of wiki pages linked to each task directly in the task view

Benefits

• Organize project documentation hierarchically (Project → Task → Wiki)
• Keep documentation close to the work context (tasks)
• Avoid inconsistencies between projects and tasks through automatic validations
• Quickly access documentation related to a specific task

Dependencies

This module requires:

• document_page_project: Module that links document pages to projects
• project: Odoo's project management module

cc @marcelsavegnago @WesleyOliveira98 @kaynnan