♻️ Refactor projwfc.x parser

The `ProjwfcParser` relied on passing a single `out_info_dict` dictionary between
several functions to store the parsed information. This made the parser code so
entangled that it was almost unreadable and difficult to trace down bugs.

Here we refactor the class to properly isolate the various parsing functions as class
methods, and make the code more readable in general. The parent class is also changed to
the `BaseParser` one, so it can rely on the basic stdout parsing this class provides.

Another substantial change is that the `.pdos` files, which can be many and are parsed
completely, are now only temporarily retrieved instead of stored in the AiiDA
repository in the `retrieved` folder.

src/aiida_quantumespresso/calculations/projwfc.py

@@ -31,12 +31,11 @@ class ProjwfcCalculation(NamelistsCalculation):
 
     xml_path = Path(NamelistsCalculation._default_parent_output_folder
                     ).joinpath(f'{NamelistsCalculation._PREFIX}.save', 'data-file-schema.xml')
-    _internal_retrieve_list = [
-        NamelistsCalculation._PREFIX + '.pdos*',
-    ]
+
     # The XML file is added to the temporary retrieve list since it is required for parsing, but already in the
     # repository of a an ancestor calculation.
     _retrieve_temporary_list = [
+        NamelistsCalculation._PREFIX + '.pdos*',
         xml_path.as_posix(),
     ]
 
@@ -60,8 +59,16 @@ def define(cls, spec):
         spec.default_output_node = 'output_parameters'
         spec.exit_code(301, 'ERROR_NO_RETRIEVED_TEMPORARY_FOLDER',
             message='The retrieved temporary folder could not be accessed.')
+        spec.exit_code(302, 'ERROR_OUTPUT_STDOUT_MISSING',
+            message='The retrieved folder did not contain the required stdout output file.')
         spec.exit_code(303, 'ERROR_OUTPUT_XML_MISSING',
             message='The retrieved folder did not contain the required XML file.')
+        spec.exit_code(310, 'ERROR_OUTPUT_STDOUT_READ',
+            message='The stdout output file could not be read.')
+        spec.exit_code(311, 'ERROR_OUTPUT_STDOUT_PARSE',
+            message='The stdout output file could not be parsed.')
+        spec.exit_code(312, 'ERROR_OUTPUT_STDOUT_INCOMPLETE',
+            message='The stdout output file was incomplete probably because the calculation got interrupted.')
         spec.exit_code(320, 'ERROR_OUTPUT_XML_READ',
             message='The XML output file could not be read.')
         spec.exit_code(321, 'ERROR_OUTPUT_XML_PARSE',
@@ -72,4 +79,6 @@ def define(cls, spec):
             message='The pdos_tot file could not be read from the retrieved folder.')
         spec.exit_code(340, 'ERROR_PARSING_PROJECTIONS',
             message='An exception was raised parsing bands and projections.')
+        spec.exit_code(350, 'ERROR_UNEXPECTED_PARSER_EXCEPTION',
+            message='The parser raised an unexpected exception: {exception}')
         # yapf: enable