fix: (Scala3) Don't navigate to enclosing symbols on go-to-definition if cursor is not on symbol

[tanishiking]

#1707

Basically the same strategy as #3792
But this PR checks isOnName inside enclosingSymbols because this Metals-version of enclosingSymbols well deals with synthetic symbols like for-flatMap and caseclass-apply. We check isOnName only if it's not on synthetic symbols or special cases (e.g. NameArg and Import).

Maybe we can make hover (for Scala3) better using this Metals-version of enclosingSymbols and it handles the issue #3792 (comment)

---

Remained issues around go-to-definition and hover are

• [Scala3] Don't show a tooltip on hover if cursor is not on a symbol #3792 (comment)
• Ignored tests in HoverTermSuite for Scala3

[tanishiking]

Moved from HoverProvider.scala

[tanishiking]

Added this case

[tanishiking]

Scala3 version of

metals/mtags/src/main/scala-2/scala/meta/internal/pc/HoverProvider.scala

Lines 308 to 324 in 35efaad

	lazy val isForName: Set[Name] = Set[Name](
	nme.map,
	nme.withFilter,
	nme.flatMap,
	nme.foreach
	)
	def isForSynthetic(gtree: Tree): Boolean = {
	def isForComprehensionSyntheticName(select: Select): Boolean = {
	select.pos == select.qualifier.pos && isForName(select.name)
	}
	gtree match {
	case Apply(fun, List(_: Function)) => isForSynthetic(fun)
	case TypeApply(fun, _) => isForSynthetic(fun)
	case gtree: Select if isForComprehensionSyntheticName(gtree) => true
	case _ => false
	}
	}

[tanishiking]

Copied from #3743

[tgodzik]

LGTM! @tanishiking could you rebase the changes?

[tanishiking]

Thank you for reviewing! rebased, merging after CI passed.