Fix: Stream objects not loaded for Plex sessions

[JonnyWong16]

Description

Objects loaded from /status/sessions have an added .session to the ehash used to lookup the PlexObject class. This adds a helper function to recursively get the PlexObject with the highest specificity. e.g. ehash = 'Stream.1.session' will return the MediaPartStream class for ehash = 'Stream.1'.

Fixes #1368
Ref.: #1328

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

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