fix DataType.copy for nested types

all nested types need a specific copy method, as some information
of EnumType (its name) and TextType are not visible in the
exported form

Change-Id: I3ef765ca35cda11b10798c68a3e2115502554c2e
Reviewed-on: https://forge.frm2.tum.de/review/c/sine2020/secop/playground/+/21441
Tested-by: JenkinsCodeReview <bjoern_pedersen@frm2.tum.de>
Reviewed-by: Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
Reviewed-by: Markus Zolliker <markus.zolliker@psi.ch>

test/test_datatypes.py

@@ -195,6 +195,7 @@ def test_EnumType():
 
     dt = EnumType('dt', a=3, c=7, stuff=1)
     copytest(dt)
+
     assert dt.export_datatype() == {'type': 'enum', 'members': dict(a=3, c=7, stuff=1)}
 
     with pytest.raises(ValueError):
@@ -396,6 +397,9 @@ def test_ArrayOf():
     with pytest.raises(ConfigError):
         dt.checkProperties()
 
+    dt = ArrayOf(EnumType('myenum', single=0), 5)
+    copytest(dt)
+
 def test_TupleOf():
     # test constructor catching illegal arguments
     with pytest.raises(ValueError):
@@ -417,6 +421,9 @@ def test_TupleOf():
 
     assert dt.format_value([3,0]) == "(3, False)"
 
+    dt = TupleOf(EnumType('myenum', single=0))
+    copytest(dt)
+
 
 def test_StructOf():
     # test constructor catching illegal arguments
@@ -449,6 +456,9 @@ def test_StructOf():
 
     assert dt.format_value({'an_int':2, 'a_string':'Z'}) == "{a_string='Z', an_int=2}"
 
+    dt = StructOf(['optionalmember'], optionalmember=EnumType('myenum', single=0))
+    copytest(dt)
+
 
 def test_Command():
     dt = CommandType()