Impl num_traits::Num for Uint (#720)

Also adds the needed `Div` and `Rem` impls to meet the required bounds

src/uint.rs

@@ -258,6 +258,15 @@ impl<const LIMBS: usize> Integer for Uint<LIMBS> {
     }
 }
 
+impl<const LIMBS: usize> num_traits::Num for Uint<LIMBS> {
+    type FromStrRadixErr = crate::DecodeError;
+
+    /// ⚠️ WARNING: `from_str_radix` impl operates in variable-time with respect to the input.
+    fn from_str_radix(str: &str, radix: u32) -> Result<Self, Self::FromStrRadixErr> {
+        Self::from_str_radix_vartime(str, radix)
+    }
+}
+
 impl<const LIMBS: usize> ConstZero for Uint<LIMBS> {
     const ZERO: Self = Self::ZERO;
 }

src/uint/div.rs

@@ -803,6 +803,24 @@ impl<const LIMBS: usize> Div<&NonZero<Uint<LIMBS>>> for Wrapping<Uint<LIMBS>> {
     }
 }
 
+impl<const LIMBS: usize> Div<Uint<LIMBS>> for &Uint<LIMBS> {
+    type Output = Uint<LIMBS>;
+
+    #[inline]
+    fn div(self, rhs: Uint<LIMBS>) -> Self::Output {
+        self / NonZero::new(rhs).expect("attempt to divide with a divisor of zero")
+    }
+}
+
+impl<const LIMBS: usize> Div<Uint<LIMBS>> for Uint<LIMBS> {
+    type Output = Uint<LIMBS>;
+
+    #[inline]
+    fn div(self, rhs: Uint<LIMBS>) -> Self::Output {
+        &self / rhs
+    }
+}
+
 impl<const LIMBS: usize> DivAssign<&NonZero<Uint<LIMBS>>> for Wrapping<Uint<LIMBS>> {
     fn div_assign(&mut self, rhs: &NonZero<Uint<LIMBS>>) {
         *self = Wrapping(self.0 / rhs);
@@ -847,6 +865,24 @@ impl<const LIMBS: usize> Rem<NonZero<Uint<LIMBS>>> for Uint<LIMBS> {
     }
 }
 
+impl<const LIMBS: usize> Rem<Uint<LIMBS>> for &Uint<LIMBS> {
+    type Output = Uint<LIMBS>;
+
+    #[inline]
+    fn rem(self, rhs: Uint<LIMBS>) -> Self::Output {
+        self % NonZero::new(rhs).expect("attempt to calculate the remainder with a divisor of zero")
+    }
+}
+
+impl<const LIMBS: usize> Rem<Uint<LIMBS>> for Uint<LIMBS> {
+    type Output = Uint<LIMBS>;
+
+    #[inline]
+    fn rem(self, rhs: Uint<LIMBS>) -> Self::Output {
+        &self % rhs
+    }
+}
+
 impl<const LIMBS: usize> RemAssign<&NonZero<Uint<LIMBS>>> for Uint<LIMBS> {
     fn rem_assign(&mut self, rhs: &NonZero<Uint<LIMBS>>) {
         *self %= *rhs