Baseline correction anchors

[lpatiny]

In the baseline correction we need to remember the points that were used as anchors otherwise we are not able to redo the processing which is annoying.

@hamed-musallam Could you have a look at this ?

[hamed-musallam]

@lpatiny

Actually, that should be the case. In the end, those anchors are saved as part of the filter, so they should still be available. I'll check what happened.

[jobo322]

I think a gif would illustrate the bug. The baseline correction filter is not editable after apply the filter. the user should start from scratch becauses the anchors are overwritten