selftests/net: Make NetDrvContEnv support queue leasing

selftests/net: Make NetDrvContEnv support queue leasing

Add a new parameter `lease` to NetDrvContEnv that sets up queue leasing
in the env.

The NETIF also has some ethtool parameters changed to support memory
provider tests. This is needed in NetDrvContEnv rather than individual
test cases since the cleanup to restore NETIF can't be done, until the
netns in the env is gone.

Signed-off-by: David Wei <dw@davidwei.uk>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260115082603.219152-16-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>