- replace runtime reflection by source generators to improve performance
- done for SvgElementFactory, property descriptors _svgPropertyAttributes and _svgEventAttributes
- no Source Generators support for net452 , added additional target framework net461
as the minimum version for source generators
- use stackalloc and out vars to reduce memory usage
- remove Linq usage to improve path parser performance
- use Span for SvgTransformConverter to improve performance
- add several benchmarks
- fixes#771, fixes#776, fixes part 2 of #767