Added float64 support

[bilinenkisi]

When i tried to use wmi.QueryNameSpace for Win32_ReliabilityStabilityMetrics with this struct:

type Win32_ReliabilityStabilityMetrics struct {
	EndMeasurementDate   time.Time `json:"end_measurement_date"`
	RelID                string    `json:"rel_id"`
	StartMeasurementDate time.Time `json:"start_measurement_date"`
	SystemStabilityIndex float64   `json:"system_stability_index"`
	TimeGenerated        time.Time `json:"time_generated"`
}

I got error for SystemStabilityIndex field: cannot load field "SystemStabilityIndex" into a "float64": unsupported type (float64)
even if i used float32 to fetch data, this time i got this error: Özel durum oluştu. (Nesne sunucuya bağlanmamış ) and also for other variable types was same that are supported by the package. So, i added float64 support.

[yusufpapurcu]

Hey, thanks for contribution 👋
Sorry I was on holidays so just saw this now, can you enrich the PR description a bit more about the issue you faced and expected behaviour? It would make it much easier to review 🙂

Or at least you can share an example that this change improves.

[bilinenkisi]

Certainly, I'll gladly enrich the PR description to provide more clarity on the issue and the expected behavior.

[yusufpapurcu]

Tested the usecase and it works! Thanks!