Add Support for Loading Gene-Annotation Files with BigWig Tracks

Description:

When using higlass-python, I'm aiming to display gene annotations alongside the BigWig track. Currently, I'm unable to identify any functionality that allows for the creation of a tileset which can then be added to a track.

Current State:
The below image showcases my output without any gene-annotation:

Expected Outcome:
For reference, I'd like the output to appear similar to this (with gene-annotation included):

It's essential for my project to be able to load the gene-annotation directly from my local machine. One potential method I've considered is to load the view configuration file and then load the gene-annotation by calling the function
[https://github.com/higlass/higlass-python/blob/91ab3dbd33e31f7f296337aaf14ab6290634b394/src/higlass/tilesets.py#L70](url).. However, my primary requirement is to facilitate this from my local server.

I would appreciate any guidance or suggestions on achieving this.

Thank you.