Skip input framework entries with missing but non-optional fields

The framework so far populated data structures with missing fields
even when those fields are defined without the &optional
attribute. When using the attribute, such entries continue to get
populated.

Update tests to reflect focus on unset fields.

testing/btest/Baseline/scripts.base.frameworks.input.emptyvals/out

@@ -1,5 +1,8 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
 {
-[2] = [b=<uninitialized>],
 [1] = [b=T]
 }
+{
+[1, 1] = [b=T],
+[2, 2] = [b=<uninitialized>]
+}