engraving: Rename Pid::SUBTYPE

[juli27]

• unused for Dynamic elements
• only remaining use is for MeasureRepeat elements
  • rename to MEASURE_REPEAT_NUMBER to better fit its purpose
• also rename the newly added subType API property
  • added in Allow plugin elements to call subtype #28386
  • might be good to have this in 4.6, but otherwise i'd have to make it backwards compatible.

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[juli27]

Some textstyles don't have a TextStyleProperty entry for TextStylePropertyType::Position, e.g. tempo text here:

MuseScore/src/engraving/style/textstyle.cpp

Lines 482 to 498 in 6d451bd

	const TextStyle tempoTextStyle { {
	{ TextStylePropertyType::FontFace, Sid::tempoFontFace, Pid::FONT_FACE },
	{ TextStylePropertyType::FontSize, Sid::tempoFontSize, Pid::FONT_SIZE },
	{ TextStylePropertyType::LineSpacing, Sid::tempoLineSpacing, Pid::TEXT_LINE_SPACING },
	{ TextStylePropertyType::SizeSpatiumDependent, Sid::tempoFontSpatiumDependent, Pid::SIZE_SPATIUM_DEPENDENT },
	{ TextStylePropertyType::FontStyle, Sid::tempoFontStyle, Pid::FONT_STYLE },
	{ TextStylePropertyType::Color, Sid::tempoColor, Pid::COLOR },
	{ TextStylePropertyType::TextAlign, Sid::tempoAlign, Pid::ALIGN },
	{ TextStylePropertyType::Offset, Sid::tempoPosAbove, Pid::OFFSET },
	{ TextStylePropertyType::FrameType, Sid::tempoFrameType, Pid::FRAME_TYPE },
	{ TextStylePropertyType::FramePadding, Sid::tempoFramePadding, Pid::FRAME_PADDING },
	{ TextStylePropertyType::FrameWidth, Sid::tempoFrameWidth, Pid::FRAME_WIDTH },
	{ TextStylePropertyType::FrameRound, Sid::tempoFrameRound, Pid::FRAME_ROUND },
	{ TextStylePropertyType::FrameBorderColor, Sid::tempoFrameFgColor, Pid::FRAME_FG_COLOR },
	{ TextStylePropertyType::FrameFillColor, Sid::tempoFrameBgColor, Pid::FRAME_BG_COLOR },
	{ TextStylePropertyType::MusicalSymbolsScale, Sid::dummyMusicalSymbolsScale, Pid::MUSICAL_SYMBOLS_SCALE },
	} };

(Introduced in #28377 ; @miiizen is this intentional?)

This causes a default initialized TextStyleProperty to be use here:

MuseScore/src/engraving/dom/textbase.cpp

Lines 3206 to 3208 in 6d451bd

	for (const auto& p : *textStyle(textStyleType())) {
	setProperty(p.pid, styleValue(p.pid, p.sid));
	}

p.pid is then whatever Pid == 0 is. This used to be the mostly unused Pid::SUBTYPE, but is Pid::SELECTED with this PR.