Please render the line labels in front of the lines.

There are multiple lines and line labels in extraLinesData. The labels overlap with other lines and obscure the text. It would be better if the labels were rendered in front of the lines.

My code
```dart:
extraLinesData: ExtraLinesData(
extraLinesOnTop: true,
verticalLines: [
if (max1LevelValue != null)
VerticalLine(
x: max1LevelValue!,
color: Colors.yellow,
strokeWidth: 3,
label: VerticalLineLabel(
show: true,
alignment: Alignment.topLeft,
padding: const EdgeInsets.only(right: 5, bottom: 5),
style: Theme.of(context).textTheme.bodySmall!,
labelResolver: (line) => '1차',
),
),
if (min1LevelValue != null)
VerticalLine(
x: min1LevelValue!,
color: Colors.yellow,
strokeWidth: 3,
label: VerticalLineLabel(
show: true,
alignment: Alignment.topRight,
padding: const EdgeInsets.only(left: 5, top: 5),
style: Theme.of(context).textTheme.bodySmall!,
labelResolver: (line) => '1차',
),
),
if (max2LevelValue != null)
VerticalLine(
x: max2LevelValue!,
color: Colors.red,
strokeWidth: 3,
label: VerticalLineLabel(
show: true,
alignment: Alignment.topLeft,
padding: const EdgeInsets.only(right: 5, bottom: 5),
style: Theme.of(context).textTheme.bodySmall!,
labelResolver: (line) => '2차',
),
),
if (min2LevelValue != null)
VerticalLine(
x: min2LevelValue!,
color: Colors.red,
strokeWidth: 3,
label: VerticalLineLabel(
show: true,
alignment: Alignment.topRight,
padding: const EdgeInsets.only(left: 5, top: 5),
style: Theme.of(context).textTheme.bodySmall!,
labelResolver: (line) => '2차',
),
),
],
horizontalLines: [
if (currentDepth != null)
HorizontalLine(
y: currentDepth!,
color: Colors.black,
strokeWidth: 1,
label: HorizontalLineLabel(
show: true,
alignment: Alignment.topRight,
style: Theme.of(context).textTheme.bodySmall!.copyWith(
color: Colors.black,
),
labelResolver: (line) => '현재 굴착 깊이',
),
),
],
),
```

Start by tracing ExtraLinesData rendering for VerticalLineLabel and HorizontalLineLabel in the line-chart path. Reproduce the supplied configuration with multiple extra lines, then verify that labels render above the lines without obscuring their text.

Written by the indexing model from the issue text.