[cwproperties] refactor properties form to make it partly overrideable easily (closes #1936782)
also fix some pitfalls on the way:
* shouldn't capitalize labels, this has to be done in translation files as desired
* form_row in CWProperties form didn't return subform as its parent class
[MESSAGES CONTROL]
disable-msg = C0301
[VARIABLES]
# Enable / disable this checker
enable-variables = yes
additional-builtins = _, display_name
[BASIC]
required-attributes=
attr-rgx = (w|[a-z_][a-z0-9_]{2,30})
variable-rgx = (w|[a-z_][a-z0-9_]{2,30})$
argument-rgx = (w|[a-z_][a-z0-9_]{2,30})$
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception