Feature: Introduced dynamic path support in FeatureFlag for custom feature flag paths.

• Users can now specify custom paths when initializing a FeatureFlag instance.
• The default path is set to 'features' if a custom path is not provided.

Enhancement: One Remote Listerner for All Features.

• each FeatureFlag instance are now listen to one stream subscription from the firebase realtime database and that stream will be disposed after all the features are being disposed (better performance).

Enhancement: Refactored and improved instance management.

• FeatureFlag instances are now managed in a way that ensure a single instance for each feature key.

Enhancement: Improved log messages for better clarity.

• Log messages have been enhanced to provide clearer information about feature flag settings.

Enhancement: Add useCache property to FeatureFlag to determine either use or not to use the cache.

Enhancement: Add dispose method to FeatureFlag to close stream subscription after the feature is disposed by the widget or manually.

Enhancement: Add dispose property to FeatureFlagBuilder to determine either dispose or keep the feature after the widget is being disposed (false by default).

Enhancement: Introduced a new class called FeatureFlagData to encapsulate feature flag data and its source information (remote or local).

Enhancement: Improved logging for platform-specific settings in the _add method.

Bug Fix: Fixed path handling issues and made it more flexible.