feat: Add option to disable BOM for text files (v96.0+) #31

PR Classification

New feature: adds an advanced option to control BOM output for extracted text files.

PR Summary

This pull request introduces an advanced setting to disable writing the BOM (Byte Order Mark) in extracted text files, supported for MKVToolNix v96.0 and above. The option is exposed in the UI and integrated throughout the extraction logic.

• gSettings.cs: Adds and persists the DisableBomForTextFiles property.
• frmOptions.Designer.cs/cs: Adds a new "Advanced Options" group with a checkbox for disabling BOM, and binds it to settings.
• gMKVExtract.cs: Passes the new setting through extraction parameters and appends --no-bom to mkvextract commands when appropriate.
• TrackParameter.cs, gMKVExtractSegmentsParameters.cs: Updates parameter classes to include the new property and related logic.