[FIX] account: Reload chart_template button unexpected unlink

Reload button appeared when no chart_template was set which
could make Odoo delete important data if clicked.
We restrict appearance of the reload button to avoid this situation.
Also adds a short description on the button to notify user of the
irreversability of the action.

Steps to reproduce:
1. Create a company (do not use the default one that has Generic CoA set) with a country set.
2. Create accounts : income, receivable and payable.
3. Create a sale journal with the income account.
4. Go to a partner detail (e.g. Deco addict), tab Accounting and set its receivable/payable accounts to the ones created above.
5. Create an invoice for that partner.
6. Go in Accounting Settings and click the reload button.
=> The invoice is deleted.

Task-3488427
OPW-3448881

closes odoo/odoo#134028

X-original-commit: a636b9386f297f9f08a38689911ca111fe597ec3
Signed-off-by: William André (wan) <wan@odoo.com>
Signed-off-by: Claire Bretton (clbr) <clbr@odoo.com>

addons/account/models/chart_template.py

@@ -172,7 +172,7 @@ class AccountChartTemplate(models.AbstractModel):
         reload_template = template_code == company.chart_template
         company.chart_template = template_code
 
-        if not reload_template:
+        if not reload_template and (not company._existing_accounting() or self.env.ref('base.module_account').demo):
             for model in ('account.move',) + TEMPLATE_MODELS[::-1]:
                 if not company.parent_id:
                     self.env[model].sudo().search([('company_id', 'child_of', company.id)]).with_context({MODULE_UNINSTALL_FLAG: True}).unlink()

addons/account/views/res_config_settings_views.xml

@@ -33,7 +33,9 @@
                                             <field name="chart_template" readonly="has_accounting_entries" required="chart_template"/>
                                         </div>
                                         <div class="mt16">
-                                             <button name="reload_template" type="object" string="Reload" class="btn-secondary ps-2 w-100" icon="fa-refresh" invisible="not has_accounting_entries"/>
+                                            <button name="reload_template" type="object" string="Reload" class="btn-secondary ps-2 w-100" icon="fa-refresh"
+                                                    title="Reload accounting data (taxes, accounts, ...) if you notice inconsistencies. This action is irreversible."
+                                                    invisible="not has_accounting_entries or not chart_template"/>
                                         </div>
                                     </div>
                                 </div>