added tile store benchmarking script

[clemsgrs]

• fix issue when requesting Path-like object to wsd with cucim backend
• benchmark tile store creation ; results suggest tile reads remains the main bottleneck

tiles=10,000
elapsed= 130.3s
throughput= 77 tiles/s

• read= 90.5%
• encode= 8.8%
• write= 0.7%

suggests no need to spend time improving writing to tar speed