Refactor component styling API for extension components

[devkanro]

This PR improves the theme's ComponentStyling API and provides a more usable and easy-to-understand pattern for extending controls.

Before:

IntUiTheme(
    themeDefinition,
    componentStyling = {
        themeDefinition.decoratedWindowComponentStyling() + themeDefinition.extensionComponentStyling() + themeDefinition.extensionComponent2Styling() + themeDefinition.extensionComponent3Styling()
    }
) {
    Box {}
}

After:

IntUiTheme(
    themeDefinition,
    componentStyling = {
        provideDecoratedWindowComponentStyling()
        provideExtensionComponentStyling()
        provideExtensionComponent2Styling()
        provideExtensionComponent3Styling()
    }
) {
    Box {}
}