Feature added: Add tracks to multiple playlist at once

Description

Changes in simple_item.xml and SimpleAdapter

• Added select functionality for playlists in simple_item.
• Implemented multi-select logic in SimpleAdapter to handle playlist selection.

Changes in SavePlaylistDialog

• Extended functionality to allow adding tracks to selected playlists.

Changes in DuplicationWarningDialog

• Enhanced dialog messages for better user understanding.

Motivation and Context

This change fixes issue #3009 (closed) which is to add tracks to multiple playlists at once

How Has This Been Tested?

By manually testing the feature, as show in Screenshots section.

Screenshots / GIFs (if appropriate):

sample1

Types of changes

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

Checklist

• I have read the CONTRIBUTING section of the README document.

Resolves

Fixes: #3009 (closed)