vm status: force int where appropriate

vm status: force int where appropriate

In the case of a running container with cgroupv2, swap would be a string,
causing a
    size.toFixed is not a function
error for the format_size call in the containers's "Summary" page in the UI.

The vmids from config_list() are already integers as the return schema expects,
while the opt_vmid passed from the status/current API call needs to be
converted.

Signed-off-by: Fabian Ebner <f.ebner@proxmox.com>