Support pasting sequence into puzzlemaker without the correct length structure

[luxaritas]

Describe your idea

There should be a method to paste in a sequence and automatically adjust the target structure to be the correct length

Motivation

When doing denovo design or ad-hoc analysis using the puzzlemaker, sometimes you have a sequence you want to work on, but no target structure. In this case it can be hard or tedious to make the length of the RNA (dictated by the target structure) exactly the right size (such that there are enough but no extra bases).

Proposed Solution

Maybe the paste dialog should be modified to include an option to change between the default behavior and resetting the target structure to match? (nb, in a similar vein it could be useful to improve how "custom numbering" is exposed as opposed to it being a magic parameter at the end of the string in cut and paste operations)

Other Information

No response