Influx2.0 Support

[whoAbhishekSah]

We need to add Influx2.0 Alerting support via Siren.

• [ ] Refactor templates engine to support multiple stacks(Cortex and Influx2.0)
• [ ] Add support for Influx2 Alert Creation and Update(Edit/Enable/Disable)
• [ ] Extend support for Influx Templates and Rules file in CLI command
• [ ] Add CRUD APIs for Notification Endpoint and Notification Rule and stitch notification rules with endpoints.