Fix parser.py Parser inheritance

In parser.py, the YamlParser is named Parser, and the JsonSchemaParser inherits from the YamlParser. This leads to problems with method signatures.

• Create new base class BaseParser or AbstractParser with all common parser functionality
• Rewrite JsonSchemaParser and create YamlParser with inheritance from base class
• Rewrite Parser to trigger a DeprecationWarning and wrap YamlParser

assigned to @i.nueske