Add window state save/restore feature

[Zakariathr22]

Description

• Adds support for saving and restoring main window size, position, scale, and maximized state between sessions.
• Introduces new settings properties and UI toggle for enabling/disabling this feature.
• Implements WindowStateHelper and WindowState classes for state management.
• Window state is restored on load and saved on close if enabled in Settings page.

Motivation and Context

• Closes Resize the window on startup #1606

How Has This Been Tested?

Manually tested

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)