[MIG] account_financial_report: Finalize migration to 12.0

* Move back to CSS and FIX

  NameError: variable @odoo-view-background-color is undefined in - on line 99, column 23:
  98 .o_account_financial_reports_page {
  99     background-color: @odoo-view-background-color;
  100     color: @odoo-main-text-color;

* Porting: parent_left does not exist anymore. Using parent_path + account code to sort report lines

* FIX js error with date object not converted to string while clicking on initial balance amount
  See https://user-images.githubusercontent.com/1033131/58337566-5d525c80-7e46-11e9-913a-3c3e0115fb3e.gif

* IMP style and metadata

* FIX tests about new date format and partner_id computed field of account.move

* FIX errors like

  2019-06-03 16:11:51,406 17857 ERROR dev_12_account_financial_report odoo.sql_db: bad query: b"\nDELETE FROM 'report_vat_report_tax'\nWHERE COALESCE(\n    write_date, create_date, (now() at time zone 'UTC'))::timestamp\n    < ((now() at time zone 'UTC') - interval '3600.0 seconds')\n"
  ERROR: syntax error at or near "'report_vat_report_tax'"
  LINE 2: DELETE FROM 'report_vat_report_tax'
                    ^
* IMP translation template and IMP Italian translation

* Remove useless comments
* Use AsIs to avoid SQL injection
* Use fields.Date methods
* Remove useless data from tests
* Improve comments
* Fix wizard.multi.charts.accounts
* Move _get_partner_ids_domain to abstract wizard
* Refactor default partners in wizard to use recordsets
* Improve js style

account_financial_report/wizard/abstract_wizard.py

@@ -0,0 +1,32 @@
+# Copyright 2019 Lorenzo Battistini @ TAKOBI
+# License AGPL-3.0 or later (http://www.gnu.org/licenses/agpl.html).
+
+from odoo import models
+
+
+class AbstractWizard(models.AbstractModel):
+    _name = 'account_financial_report_abstract_wizard'
+    _description = 'Abstract Wizard'
+
+    def _get_partner_ids_domain(self):
+        return [
+            '&',
+            '|',
+            ('company_id', '=', self.company_id.id),
+            ('company_id', '=', False),
+            '|',
+            ('parent_id', '=', False),
+            ('is_company', '=', True),
+        ]
+
+    def _default_partners(self):
+        context = self.env.context
+        if (
+            context.get('active_ids') and
+            context.get('active_model') == 'res.partner'
+        ):
+            partners = self.env['res.partner'].browse(context['active_ids'])
+            corp_partners = partners.filtered('parent_id')
+            partners -= corp_partners
+            partners |= corp_partners.mapped('commercial_partner_id')
+            return partners.ids