Availability of Network Offering not taken into account in Web Interface

### problem

When loading the CreateIsolatedNetworkForm form, the availability is not taken into account in selecting the default network offering.
It seems the issue is also present in CreateSharedNetworkForm and CreateL2NetworkForm

### versions

Running 4.22.0 but issue still present in main branch

### The steps to reproduce the bug

1. Add network
2. Check if the pre-selected network is the one with Required availability

### What to do about it?

https://github.com/apache/cloudstack/blob/6dc259c7dab7bee0c4ff731271c61e2f2ee97532/ui/src/views/network/CreateIsolatedNetworkForm.vue#L565C1-L565C69
Change this line to select the first element with the availability "Required" instead of the first of the list (That is sorted by ID by default)

Empieza en ui/src/views/network/CreateIsolatedNetworkForm.vue alrededor de la línea 565 y, a continuación, inspecciona la lógica correspondiente de selección predeterminada en CreateSharedNetworkForm y CreateL2NetworkForm. Reproduce el flujo Add network y verifica que la oferta preseleccionada sea la primera con Required availability en lugar de ser simplemente la primera oferta de la lista ordenada por ID.

Escrito por el modelo de indexación a partir del texto del issue.