This adds support to display vertices lines over the profile graph to
display indicator at the location of the curve's vertices.
This is achieved with mainly 2 changes:
- `QgsProfilePlotRenderer::setSubsectionsSymbol()` allows to set the
line symbol of the vertical lines
- `renderSubsectionsIndicator` generates and renders the vertical
lines. It is called by `QgsProfilePlotRenderer::renderToImage()`.
The original workaround was only supposed to apply to QList/
QVector of QVariantMaps. By replacing them all in sip we
break mapping of signals defined in c++ which are emitted
by Python code.
Fixes exceptions after running processing algorithms in Qt6
builds.
