v1: patches + improvements

[ndonkoHenri]

Summary by Sourcery

Refactor and improve storage paths, responsive design, and control handling across Dart and Python implementations of the Flet framework

New Features:

• Added ResponsiveRowBreakpoint enum in Python
• Introduced platform-specific method checks for storage paths

Enhancements:

• Redesigned StoragePaths service to use invoke method pattern
• Improved responsive row breakpoint handling
• Simplified control and shader mask implementations
• Added platform-specific method checks in Python implementation

Chores:

• Cleaned up unused imports
• Simplified error handling and control logic

[FeodorFitsner]

I'm still not completely sold we should introduce a lot of "specific" types, like OptionalControl where you have to go there and see what that type really means. Moreover, starting from Python 3.11 it has nicer syntax: Control | None, so eventually we won't need that at all.