[nikryden]

This pull request improves the usability of the application's toolbar and window controls. The main changes introduce a dropdown menu for the "Open" button in the toolbar, allowing users to choose between opening a single file, multiple files, or a folder. Additionally, the window title bar is enhanced to support double-clicking for maximize/restore functionality, and a minor margin adjustment is made for better UI alignment.

Toolbar usability improvements:

• The "Open" button in the toolbar (MainWindow.xaml) is now a dropdown button with a context menu, offering options to open a log file, multiple files, or a folder. This enhances user accessibility and streamlines file opening operations.
• Added OpenDropdown_Click handler in MainWindow.xaml.cs to display the dropdown menu when the "Open" button is clicked.

Window controls and UI tweaks:

• Enhanced the title bar so that double-clicking maximizes or restores the window, improving standard window behavior.
• Increased the left margin of the version text in the main window for improved visual spacing.