feat: creating new mx_ suite of macros!

also adding new mx_getcode macro

tests/base/mp_assert.test.sas

@@ -0,0 +1,15 @@
+/**
+  @file
+  @brief Testing mp_assert macro
+  @details This is quite "meta".. it's just testing itself
+
+  <h4> SAS Macros </h4>
+  @li mp_assert.sas
+
+**/
+
+%mp_assert(
+  iftrue=(1=1),
+  desc=Checking result was created,
+  outds=work.test_results
+)