[FIX] account_financial_report: Refactor tests

Use core account test base, helping to ensure we have the correct accounting environment setup.
If any of the localization modules are loaded, this will make this tests be skipped, instead of simply failing

TT28423

account_financial_report/__manifest__.py

@@ -6,7 +6,7 @@
 # License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
 {
     "name": "Account Financial Reports",
-    "version": "14.0.1.0.0",
+    "version": "14.0.1.0.1",
     "category": "Reporting",
     "summary": "OCA Financial Reports",
     "author": "Camptocamp SA,"