feat(alertmanager): integrate with ruler (#7222)

### Summary

Integrate the new implementations of the alertmanager along with changes to the ruler. This change can be broadly categoried into 3 parts:

#### Frontend
- The earlier `/api/v1/alerts` api was double encoding the response in json and sending it to the frontend. This PR fixes the json response object. 

For instance, we have gone from the response `{
    "status": "success",
    "data": "{\"status\":\"success\",\"data\":[{\"labels\":{\"alertname\":\"[platform][consumer] consumer is above 100% memory utilization\",\"bu\":\"platform\",\"......
}` to the response `{"status":"success","data":[{"labels":{"alertname":"[Metrics] Pod CP......`

- `msteams` has been changed to `msteamsv2` wherever applicable

#### Ruler
The following changes have been done in the ruler component:

- Removal of the old alertmanager and notifier
- The RuleDB methods `Create`, `Edit` and `Delete` have been made transactional
- Introduction of a new `testPrepareNotifyFunc` for sending test notifications
- Integration with the new alertmanager

#### Alertmanager
Although a huge chunk of the alertmanagers have been merged in previous PRs (the list can be found at https://github.com/SigNoz/platform-pod/issues/404), this PR takes care of changes needed in order to incorporate it with the ruler

- Addition of ruleId based matching
- Support for marshalling the global configuration directly from the upstream alertmanager
- Addition of orgId to the legacy alertmanager
- Support for always adding defaults to both routes and receivers while creating them
- Migration to create the required alertmanager tables
- Migration for msteams to msteamsv2 has been added. We will start using msteamv2 config for the new alertmanager and keep using msteams for the old one.

#### Related Issues / PR's

Closes https://github.com/SigNoz/platform-pod/issues/404
Closes https://github.com/SigNoz/platform-pod/issues/176

go.mod

@@ -71,7 +71,6 @@ require (
 	go.uber.org/zap v1.27.0
 	golang.org/x/crypto v0.32.0
 	golang.org/x/exp v0.0.0-20240506185415-9bf2ced13842
-	golang.org/x/net v0.33.0
 	golang.org/x/oauth2 v0.24.0
 	golang.org/x/sync v0.10.0
 	golang.org/x/text v0.21.0
@@ -267,6 +266,7 @@ require (
 	go.opentelemetry.io/proto/otlp v1.3.1 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
 	golang.org/x/mod v0.22.0 // indirect
+	golang.org/x/net v0.33.0 // indirect
 	golang.org/x/sys v0.29.0 // indirect
 	golang.org/x/time v0.6.0 // indirect
 	golang.org/x/tools v0.28.0 // indirect