Generally revise electric bicycle laws

This bill revises Montana's electric bicycle laws by updating definitions and amending specific sections of the state's motor vehicle code. It directly affects vehicle owners, law enforcement, and transportation officials by clarifying terminology for various vehicle types. The key provision adds new definitions for terms like "authorized agent," "autocycle," and "commercial motor vehicle" to ensure consistent understanding across regulations. These changes aim to modernize the legal framework governing electric bicycles and related vehicles without altering existing operational rules.