Upgrade to Python 3.10

[newmana]

Features:

• Support Python 3.10.x
• Added quality checks black, ruff and mypy and fixed appropriate source code.
• Copy parameters now work with the same semantics as scanpy.
• Library upgrades for leidenalg, louvain, numba, numpy, scanpy, and tensorflow.
• .datasets.xenium_sge - loads Xenium data (and caches it) similar to scanpy's visium_sge call.

Bug fixes:

• Xenium TIFF and cell positions are now aligned.
• Consistent with type annotations - mainly missing None annotations.
• pl.cluster_plot - Does not keep colours from previous runs when clustering.
• pl.trajectory.pseudotime_plot - Fix typing of cluster values in .uns["split_node"].
• Removed datasets.example_bcba - Replaced with wrapper for scanpy.visium_sge.
• Moved spatials directory to spatial, cleaned up pl and tl packages.