feat: mf_islibds() macro to test if a library.dataset reference is syntactically valid

tests/crossplatform/mf_islibds.test.sas

@@ -0,0 +1,46 @@
+/**
+  @file
+  @brief Testing mf_islibds macro
+
+      %put %mf_islibds(work.something)=1;
+      %put %mf_islibds(nolib)=0;
+      %put %mf_islibds(badlibref.ds)=0;
+      %put %mf_islibds(w.t.f)=0;
+
+  <h4> SAS Macros </h4>
+  @li mf_islibds.sas
+  @li mp_assert.sas
+
+**/
+
+%mp_assert(
+  iftrue=(
+    %mf_islibds(work.something)=1
+  ),
+  desc=%str(Checking mf_islibds(work.something)=1),
+  outds=work.test_results
+)
+
+%mp_assert(
+  iftrue=(
+    %mf_islibds(nolib)=0
+  ),
+  desc=%str(Checking mf_islibds(nolib)=0),
+  outds=work.test_results
+)
+
+%mp_assert(
+  iftrue=(
+    %mf_islibds(badlibref.ds)=0
+  ),
+  desc=%str(Checking mf_islibds(badlibref.ds)=0),
+  outds=work.test_results
+)
+
+%mp_assert(
+  iftrue=(
+    %mf_islibds(w.t.f)=0
+  ),
+  desc=%str(Checking mf_islibds(w.t.f)=0),
+  outds=work.test_results
+)