fix: use the correct formatter for the description

[srikanthccv]

Summary

Here is how the conversion happens in alerts.

1. The y-axis unit is the unit of the underlying data. For example, for durationNano, ns is the unit.
2. The user selects the y-axis unit for an alert
3. At the alert condition step, they have a convenient way to define the threshold/target instead of writing it in the same unit as the underlying data. For example, they can say above 1000 ms rather than above 1000000000

How do we do the comparison?

1. We send the query without any unit knowledge to ClickHouse.
2. The results are fetched and compared against the threshold/target
3. When comparing, we take the threshold/target value and convert it to the same unit as the underlying data here

   signoz/pkg/query-service/rules/thresholdRule.go

   Lines 168 to 176 in b0b69c8

   	func (r *ThresholdRule) targetVal() float64 {
   	if r.ruleCondition == nil || r.ruleCondition.Target == nil {
   	return 0
   	}
   	unitConverter := converter.FromUnit(converter.Unit(r.ruleCondition.TargetUnit))
   	value := unitConverter.Convert(converter.Value{F: *r.ruleCondition.Target, U: converter.Unit(r.ruleCondition.TargetUnit)}, converter.Unit(r.Unit()))
   	return value.F
   	}

Now that the targetVal is already converted to same unit as data, we need to use the same formatter.

[github-actions]

Build Error! No Linked Issue found. Please link an issue or mention it in the body using #<issue_id>

[github-actions]

Build Error! No Linked Issue found. Please link an issue or mention it in the body using #<issue_id>