Add an argument to allow the last compiled page to 'adopt' up to X remaining images even if it's already hit a valid breakpoint

[bajuwa]

This will combat scenarios where the final compiled page is just a single image or two, and it would have been more beneficial to add them to the previous page instead of having them be a page all on their own.

[bajuwa]

This may conflict with the concept of 'maximum height' that is also requested. This ticket could be modified to instead behave like this: After hitting the minimum height, if the total remaining height of all remaining images would still result in a page under the maximum height then 'adopt' those orphaned pages as well.

This would, however, need to define which is the stronger requirement: If the min height is reached, but the remaining orphans result in a page taller than the max height, but they also do not reach the min-height for a standalone page, what do we do?
My current preference/proposal would be to continue current behaviour: min-height of the last page is not strict

[bajuwa]

The issue was resolved by adding a new field that mimics 'minimum height per page' but specifically applies to the last page. All height formats from 'per page' also apply for 'last page'. and GUI has been updated to include this field