Select tuplet when calling next-element prev-element actions

[efu98]

Resolves: #17600

Select tuplet when calling action next-element and prev-element

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[shoogle]

Thanks for this! You've nearly solved the next-element function (but not quite), and you also need to do the same in the other direction with previous-element (Alt+Left).

From #17600 (comment):

If you go in the other direction with Alt+Left then the elements should be selected in reverse order.

[Jojo-Schmitz]

Going back does not select them in reverse order, both directions select the tuplet first.
May not be a great deal, at least it does get selected both ways and sort of it is the last and first element at the same time in a way.

[shoogle]

@Jojo-Schmitz is right, when going backwards it's not in reverse order.

Here's what we want to see:

Forwards (Alt+Right)	Backwards (Alt+Left)
1. D 2. Tuplet 3. E 4. F 5. G 6. A	6. A 5. G 4. F 3. E 2. Tuplet 1. D