NxPrimaryButton class

A customizable filled button widget with consistent styling.

This button is designed to be used as the primary call-to-action in forms and dialogs. It uses Flutter's FilledButton to provide a prominent, filled appearance that draws attention to the primary action.

The button's appearance can be customized using:

• buttonStyle - Complete style override using Flutter's ButtonStyle
• buttonTextStyle - Text style for the button label
• margin - Space around the button (defaults to vertical margin of 16)
• buttonWidth - Width of the button (defaults to full width)
• buttonHeight - Height of the button

The buttonStyle controls the button's appearance (background, elevation, etc.) while buttonTextStyle independently controls the text appearance.

Example:

NxPrimaryButton(
  text: 'Submit',
  onPressed: () {
    // Handle button press
  },
  buttonWidth: 155,
  buttonHeight: 50,
  margin: EdgeInsets.all(8),
  buttonTextStyle: TextStyle(fontSize: 16),
  buttonStyle: FilledButton.styleFrom(
    backgroundColor: Colors.blue,
    foregroundColor: Colors.white,
  ),
)