Implement individual file type association/disassociation in FileAssociationDialog. Added functionality to dynamically update button labels and actions for each file type.

[cary-rowen]

Link to issue number:

Fixed #255

Summary of the issue:

Currently, there is no way to associate or disassociate individual file types within the application. This functionality is necessary to provide users with more granular control over file associations.

Description of how this pull request fixes the issue:

This pull request introduces the ability to associate or disassociate each file type individually. The user can now manage file associations more flexibly through the updated UI. The code ensures that the button labels update dynamically based on the current association status of each file type.

Testing performed:

• Verified that buttons update their labels correctly after associating or disassociating a file type.
• Confirmed that the appropriate registry keys are modified when file types are associated or disassociated.
• Checked that the application responds correctly when the new functionality is invoked through the UI.

Known issues with pull request:

No known issues at this time.