Add ability to select/lock/unlock logos and delete resources

[JonnyWong16]

Description

Add ability to select/lock/unlock logos and delete resources.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated the docstring for new or existing methods
• I have added tests when applicable

[Copilot]

Pull Request Overview

This PR adds comprehensive logo support to Plex objects, enabling logo selection, locking/unlocking, and deletion capabilities. The implementation extends existing image management patterns to logos and adds resource deletion methods.

Key Changes:

• Implemented logo locking/unlocking functionality (previously marked as not implemented)
• Added deleteLogo(), deleteArt(), deletePoster(), and deleteTheme() methods for resource cleanup
• Extended test coverage to include logo operations across all relevant media types

Reviewed Changes

Copilot reviewed 11 out of 11 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
plexapi/mixins.py	Core implementation: Added delete methods for images/themes, implemented logo locking, added logo property, and updated setLogo() from raising NotImplementedError to selecting logos
plexapi/audio.py	Added LogoMixin and LogoUrlMixin to Artist, Album, and Track classes
plexapi/collection.py	Added LogoMixin to Collection class
plexapi/photo.py	Added LogoMixin and LogoUrlMixin to Photoalbum and Photo classes
plexapi/playlist.py	Added LogoMixin to Playlist class
tests/test_mixins.py	Added test helpers for logo operations and delete functionality validation
tests/test_video.py	Added logo test coverage for Movie, Show, Season, and Episode; uncommented previously disabled Episode art test
tests/test_audio.py	Added logo test coverage for Artist, Album, and Track
tests/test_collection.py	Added logo test coverage for Collection
tests/test_photo.py	Added logo test coverage for Photoalbum
tests/test_playlist.py	Added logo test coverage for Playlist

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}