[FIX] account: tests reconciliation helper class

Before this commit, test reconciliation was inherited by
test reconciliation widget.
It made the actual test_xx functions of the former
being executed twice

After this commit, we create an intermediary test class for setUp and helpers
And the tests for each class execute only once

addons/account/tests/test_reconciliation.py

@@ -5,7 +5,8 @@ import time
 import unittest
 
 
-@tagged('post_install', '-at_install')
+# TODO in master
+# The name of this class should be TestReconciliationHelpers
 class TestReconciliation(AccountingTestCase):
 
     """Tests for reconciliation (account.tax)
@@ -166,6 +167,10 @@ class TestReconciliation(AccountingTestCase):
         supplier_move_lines = bank_stmt.move_line_ids
         return customer_move_lines, supplier_move_lines
 
+
+@tagged('post_install', '-at_install')
+class TestReconciliationExec(TestReconciliation):
+
     def test_statement_usd_invoice_eur_transaction_eur(self):
         customer_move_lines, supplier_move_lines = self.make_customer_and_supplier_flows(self.currency_euro_id, 30, self.bank_journal_usd, 42, 30, self.currency_euro_id)
         self.assertRecordValues(customer_move_lines, [