feat: creating new mx_ suite of macros!

also adding new mx_getcode macro

tests/base/mf_getfilesize.test.sas

@@ -0,0 +1,30 @@
+/**
+  @file
+  @brief Testing mf_getfilesize macro
+
+  <h4> SAS Macros </h4>
+  @li mf_getfilesize.sas
+  @li mp_assert.sas
+  @li mp_assertscope.sas
+
+**/
+
+data test;
+  x=1;
+run;
+
+%mp_assertscope(SNAPSHOT)
+%put %mf_getfilesize(libds=work.test)
+%mp_assertscope(COMPARE)
+
+%mp_assert(
+  iftrue=(&syscc=0),
+  desc=Checking syscc
+)
+
+%put %mf_getfilesize(libds=test);
+
+%mp_assert(
+  iftrue=(&syscc=0),
+  desc=Checking syscc with one level name
+)