feat(bbox): add bounding box implementation with serialization

Add initial implementation of the `BBox` struct in the `bbox` module,
including basic operations and serialization/deserialization support
with Serde.

bbox/src/traits/min.rs

@@ -0,0 +1,27 @@
+pub trait Min: Sized + Copy {
+    fn min(self, other: Self) -> Self;
+}
+
+macro_rules! impl_min {
+    ($($t:ty),*) => {
+        $(
+            impl Min for $t {
+                fn min(self, other: Self) -> Self {
+                    Ord::min(self, other)
+                }
+            }
+        )*
+    };
+    (float $($t:ty),*) => {
+        $(
+            impl Min for $t {
+                fn min(self, other: Self) -> Self {
+                    Self::min(self, other)
+                }
+            }
+        )*
+    };
+}
+
+impl_min!(usize, u8, u16, u32, u64, u128, isize, i8, i16, i32, i64, i128);
+impl_min!(float f32, f64);