InCase has indent width of case

[som-snytt]

Fixes #25002

Set the indent width of InCase using the offset of case instead of in handleNewLine.

[som-snytt]

Needs a good tweak.

For example, this seems to look like a badly formed function literal because of the arrow, which is supposed to close the region.

    sym.namedType.allMembers.iterator.map(_.symbol)
      .collect {
         case sym if
          (!sym.is(dotc.core.Flags.ModuleVal) || sym.is(dotc.core.Flags.Given)) &&
          !sym.flags.isAllOf(dotc.core.Flags.Enum | dotc.core.Flags.Case | dotc.core.Flags.JavaStatic) =>
              sym.asInstanceOf[Symbol]
      }.toList