Fixes #16236

This PR implements a visual progress update while cutting bookmarked lines, particularly useful for large files. The following improvements were made:

• Displays progress in the status bar every 5000 lines (can be tuned).
• Keeps the UI responsive by processing pending messages.
• Adds a cancel button through a dialog, allowing users to stop the operation midway.
• Ensures clipboard is updated only with the lines processed before cancellation.

Notes:

• The progress status is sent via NPPM_SETSTATUSBAR.
• A modeless dialog with a Cancel button is added using CreateDialogParam.
• A _cancelCutOperation flag is added to gracefully exit the loop when cancellation is requested by the user.
• The code uses PeekMessage to maintain UI responsiveness, thus eliminating the screen freeze

Tested on:

• Windows 10, Visual Studio 2022.
• Files with ~90,000 bookmarked lines.

Testing Snippets.docx