support roi extraction of 2-channel data in GUI

[itsb]

Resolves #1084

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (193e7f1) 55.15% compared to head (1a1bd5b) 55.15%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1086 +/- ## ======================================= Coverage 55.15% 55.15% ======================================= Files 42 42 Lines 4957 4957 ======================================= Hits 2734 2734 Misses 2223 2223 ```

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