Rename parse.retree.BaseVisitor to pass-through (#500)

We rename `parse.retree.BaseVisitor` to `PassThroughVisitor` in
alignment with the naming used for the generated SDKs. The name "base
visitor" is also a bit of a misnomer as it insinuates some kind of an
abstract class, while the pass-through visitor is explicitly a concrete
class.

aas_core_codegen/parse/retree/__init__.py

@@ -35,7 +35,7 @@
 Visitor = _types.Visitor
 Transformer = _types.Transformer
 
-BaseVisitor = _visitor.BaseVisitor
+PassThroughVisitor = _visitor.PassThroughVisitor
 
 dump = _stringify.dump
 

aas_core_codegen/parse/retree/_fix.py

@@ -9,7 +9,7 @@
 )
 
 
-class _FixForUTF16Regex(retree_visitor.BaseVisitor):
+class _FixForUTF16Regex(retree_visitor.PassThroughVisitor):
     """
     Modify the pattern in-place so that UTF-32 can be dealt by UTF-16-only regex engine.
 

aas_core_codegen/parse/retree/_visitor.py

@@ -15,7 +15,7 @@
 from aas_core_codegen.parse.tree import FormattedValue
 
 
-class BaseVisitor(Visitor):
+class PassThroughVisitor(Visitor):
     """Visit all the nodes recursively without any action."""
 
     def visit_regex(self, node: Regex) -> None:

aas_core_codegen/xsd/main.py

@@ -124,7 +124,7 @@ def _undo_escaping_backslash_x_u_and_U_in_pattern(pattern: str) -> str:
     return "".join(parts)
 
 
-class _AnchorRemover(parse_retree.BaseVisitor):
+class _AnchorRemover(parse_retree.PassThroughVisitor):
     """
     Remove anchors from a regex in-place.