Add container size to seasons request to allow more than 20 to be pulled

[richardgetz]

Description

Added &X-Plex-Container-Size={self.childCount} to seasons function in the Show class. This allows a user to pull all seasons for a shot in one call. Previously, this would be limited to the default container size (20).

Fixes #1018

Type of change

Please delete options that are not relevant.

• [x] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] This change requires a documentation update

Checklist:

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