Adds std::format support for math types

Adds `std::formatter` specializations for `Mat`, `Vector2`, `Vector3`, and `Vector4` types, enabling the use of `std::format` for these types.

This simplifies formatting and printing of these mathematical objects, improving code readability and consistency.

Also adds a hash function specialization for Vector3.

tests/general/unit_test_mat.cpp

@@ -125,7 +125,7 @@ TEST_F(UnitTestMat, Clear)
 
 TEST_F(UnitTestMat, ToString)
 {
-    const std::string str = m2.to_string();
+    const std::string str = std::format("{}", m2);
     EXPECT_FALSE(str.empty());
     EXPECT_EQ(str, "[[    1.000,     2.000]\n [    3.000,     4.000]]");
 }