Fix missing checks that args match top-level params

Fixes kaitai-io/kaitai_struct#1086

Until now, top-level types were treated the same as opaque types, which
had the unintended consequence that arguments passed to top-level types
were not validated against the number and data types of declared
parameters.

This commit fixes the `formats_err` tests added in
kaitai-io/kaitai_struct_tests@9d518e6 -
more specifically, these failures in `sbt test` output are now fixed:

```
- params_call_bad_type_top_import *** FAILED ***
  []
    did not equal
  [params_call_bad_type_top_import.ksy: /seq/0/type:
  	error: can't pass argument #1 of type CalcFloatType into parameter `has_trailer` of type CalcBooleanType
  ] (SimpleMatchers.scala:34)
- params_call_bad_type_top_local *** FAILED ***
  []
    did not equal
  [params_call_bad_type_top_local.ksy: /seq/0/type:
  	error: can't pass argument #1 of type CalcFloatType into parameter `has_trailer` of type CalcBooleanType
  ] (SimpleMatchers.scala:34)
- params_call_too_many_top_import *** FAILED ***
  []
    did not equal
  [params_call_too_many_top_import.ksy: /seq/0/type:
  	error: parameter count mismatch: 2 declared, but 3 used
  ] (SimpleMatchers.scala:34)
- params_call_too_many_top_local *** FAILED ***
  []
    did not equal
  [params_call_too_many_top_local.ksy: /seq/0/type:
  	error: parameter count mismatch: 2 declared, but 3 used
  ] (SimpleMatchers.scala:34)
```

shared/src/main/scala/io/kaitai/struct/datatype/DataType.scala

@@ -174,7 +174,7 @@ object DataType {
       classSpec.get.isExternal(curClass)
     def isOpaque = {
       val cs = classSpec.get
-      cs.isTopLevel || cs.meta.isOpaque
+      cs.meta.isOpaque
     }
   }
   case class UserTypeInstream(