feat(templates): add localized push templates and actions

Share template keys across email and push with independent editors and revisions. Render localized actions and preserve version-one delivery.

Ref: IT-1627

HrynCo.NotificationService.DAL.EF/Entities/PushTemplateVariableData.cs

@@ -0,0 +1,7 @@
+namespace HrynCo.NotificationService.DAL.EF.Entities;
+
+internal sealed class PushTemplateVariableData
+{
+    public required string Name { get; set; }
+    public bool Required { get; set; }
+}