UI: Please change memory setting in flex compute offering from MiB to GiB

### The required feature described as a wish

As a user, I'd like to be able to set the memory size of my instances in GiB without having to calculate the correct MiB value.
Entering values in MiB tends to lead to entering round numbers of 1,000. This then results in odd GiB values.
If a VM with less than 1 GiB is ever actually needed, you can enter 0.5 GiB, for example.
However, this use case is likely to occur much less frequently than higher GiB values.

Maybe it could include a drop-down menu next to the value that uses GiB as the default but also allows MiB to be selected. But I think GiB is the most helpful for most people.

Beginne damit, die UI des Flex-Compute-Angebots und das Speicherfeld zu lokalisieren, das derzeit MiB-Werte akzeptiert, und prüfe anschließend alle nahegelegenen UI-Tests. Erledigt ist die Aufgabe, wenn Benutzer standardmäßig Speicher in GiB eingeben können, einschließlich gebrochener Werte wie 0.5, mit der angeforderten MiB-Alternative, sofern das bestehende Design eine Einheitenauswahl unterstützt.

Vom Indexierungsmodell aus dem Issue-Text verfasst.