Add option to paste over existing content without erasing it

Your idea

I advocate for an add-functionality.
The notes that are copied onto the clipboard, should be able to be add to a bar, without the notes that already are in that bar, being deleted.
So if you have The Notesequence C B A assigned to the flutes and for example E E C, to the oboes, but later decide you want both to be played by the flutes, you just copy the E E C sequence and add it to the C B A sequence.
So The flutes play C and E together, then B and E and then A and C.

Problem to be solved

If you want to copy notes to a bar that is already filled with notes, you can't do so without deleting the notes that are already in that bar.
This means that there is a need to either create another flute section in the score or go through the effort of adding the notes manualy.

Prior art

No response

Additional context

You could further add on that feature and give the option off adding an octave higher or lower.
This way, the effort of for example writing melodies which are doubled in another octave, much easier.
You could just:

1. Copy the melody
2. Right click the start of the melody
3. Click on "Add an octave lower/higher"

Start by reviewing the proposed workflow in the issue: copying a note sequence, selecting the destination bar, and choosing an add action. Define the expected behavior for combining existing and pasted notes, including the optional octave shift, then add coverage for the completed behavior; no files or tests are identified in the issue.