Add support for rendering FloatingButton secondary button standalone

[adids1221]

Description

Adds support for rendering FloatingButton component with only the secondary button. When secondaryButton is provided without button prop, the component now renders the secondary button with horizontal layout styling and outline stroke. Added isSecondaryOnly getter to detect this state and shouldSecondaryButtonFlex getter to handle flex behavior. Fixed fullWidth margin consistency for secondary button when rendered alone to ensure proper centering with equal horizontal margins using marginHorizontal: Spacings.s5.

Changelog

FloatingButton - Added support for rendering secondary button standalone.

Additional info

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