Evaluate pedestal correlation across multiple runs

[graeme-winter]

We took N pedestal runs a few times back-to-back - evaluate how much these differ

[graeme-winter]

Example input:

2023-06-26-11-13-46_darks
2023-06-26-11-16-21_darks
2023-06-26-11-17-44_darks
2023-06-26-11-18-58_darks
2023-06-26-11-20-12_darks
2023-06-26-11-21-26_darks
2023-06-26-11-22-40_darks
2023-06-26-11-23-54_darks
2023-06-26-11-25-08_darks
2023-06-26-11-26-22_darks
2023-06-26-11-27-36_darks
2023-06-26-11-28-49_darks
2023-06-26-11-30-03_darks
2023-06-26-11-31-17_darks
2023-06-26-11-32-31_darks
2023-06-26-11-33-46_darks
2023-06-26-11-35-00_darks
2023-06-26-11-36-13_darks
2023-06-26-11-37-28_darks
2023-06-26-11-38-42_darks
2023-06-26-11-39-56_darks
2023-06-26-11-41-10_darks

[graeme-winter]

Will look at alongside #11 since these are substantially overlapped issues