Fix #293113: Number instruments when using New Score Wizard

[IsaacWeiss]

When creating a new score and choosing instruments, all duplicates will be automatically numbered (e.g., "Violin" and "Violin" will be "Violin 1" and "Violin 2". Algorithm is probably wasteful; help requested.

The format "[default text] [digit]" may not be correct in all languages, but at the moment I don't know any way around that. The similar PR #2953 (for part names) did not address translations.

[GaspardPO]

What happens if you have 2 times the same instrument?
e.g. bass and treble for piano, or tab and part for guitar.

[IsaacWeiss]

Multiple staves within the same instrument share one name between them. I'm not sure what you're asking.

[dmitrio95]

The format "[default text] [digit]" may not be correct in all languages, but at the moment I don't know any way around that.

It could (at least partially) be done via translations mechanism. Setting part name

part->setPartName((part->partName() + QStringLiteral(" %1").arg(n)));

can be rewritten like

/*: Numbering of parts with equal names, where %1 stands for part name and %2 is a number. Example: "%1 %2" would expand to "Violin 1", "Violin 2" etc. */
part->setPartName(tr("%1 %2").arg(part->partName()).arg(n));

where the comment in /*: */ is a translator comment which will explain the context for translators on Transifex. That will allow translators to define the order of part name and number depending on a particular language.