feat: Add bit_width for unsigned NonZero<T>

[sorairolake]

• Tracking issue: Tracking Issue for uint_bit_width #142326

This pull request adds a method to the unsigned NonZero<T> that return the minimum number of bits required to represent a value.

This can be achieved by using the get method and the methods added in #142328, but I think adding the NonZero::bit_width method is useful because it accomplishes the same thing a little more succinctly.

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