[IMP] account_statement_import_online[_ponto] improvements.

1. Find partner if ther already is a bank account with the right IBAN;
2. Store (and display) raw import data to help in problem determination;
3. Make it easy to extend the parsing of import data;
4. Apply some clean coding principles.

account_statement_import_online/__manifest__.py

@@ -23,6 +23,7 @@
         "wizards/online_bank_statement_pull_wizard.xml",
         "views/actions.xml",
         "views/account_journal.xml",
+        "views/account_bank_statement_line.xml",
         "views/online_bank_statement_provider.xml",
     ],
     "installable": True,