Remember compatibility option for joining files

[rieje]

• [X] Check out all the menus and keyboard shortcuts. Maybe the feature already exists?
• [X] Try with the newest version from GitHub
• [X] Read the documentation and FAQ, Known issues, Troubleshooting to see if the feature already exists
• [X] See if someone already suggested this under Issues or Discussions

Description

I use the merging/concatenating feature a lot and a simple feature request would be to remember whether the compatibility option was checked and re-use this option instead of checking the box to do a check when this joining window pops up every time. If previous checked, check for comparability immediately. I would prefer checking compatibility as default (not sure how sensible this is for other people's cases), but remembering the option fulfills all usecases.

[snakecase]

I would like to add that this feature could actually be a bug of not saving merge options between sessions. For example, the settings below get reset on program exit though it looks like they are supposed to be kept between runs.

[mifi]

I agree this makes sense to remember, just haven't had time to implement yet

[mifi]

I added this to #371 - closing this issue