fix: remove direct reference to CardThemeData for Flutter version compatibility

[JohnettJobben1]

Direct usage of CardThemeData causes build failures on older Flutter SDKs
where this type does not exist. Replaced it with untyped (inferred or dynamic)
references to ensure compatibility across versions.

Access to CardTheme properties (color, elevation, clipBehavior, margin)
is now handled dynamically, maintaining functionality without breaking builds
on earlier versions of Flutter.

Details

• Removed direct reference to CardThemeData.
• Used type inference to avoid compile-time dependency on version-specific types.

[JohnettJobben1]

@krishna-pietech please review.

[JohnettJobben1]

#359 #356