[win32] Refactor path to support multiple handles

This commit refactors Path in the win32 implementation to better
support multiple handles for different zoom settings of a Path when
monitor-specific scaling is enables. The previous implementation
only applied adaptions on the path to the initial handle and relied
on the path not to be changed after usage. This doesn't cover all
scenarios and can lead to incompletely rendered path when reusing Path
object over different zoom settings.

Author: akoch-yatta