(rootful) docker-compose now updates network MTU

Previously, the following network block did not update using
docker-compose:

```
networks:
  default:
    driver: bridge
    driver_opts:
      mtu: 9000
```

In the API, the network options were previously not being handled when the
network was being created. I translated the docker options into podman
options, and added the options to the network.

When doing `podman network inspect <network>`, the results now contain
`"mtu": "9000"`

Fixes: #14482

Signed-off-by: Jake Correnti <jcorrenti13@gmail.com>

test/compose/update_network_mtu/docker-compose.yml

@@ -0,0 +1,26 @@
+version: '3.7'
+
+services:
+  nginx:
+    image: alpine
+    ports:
+      - 8000:5000
+    networks:
+      - default
+      - macvlan_net
+
+networks:
+  default:
+    driver: bridge
+    driver_opts:
+      com.docker.network.bridge.name: docker0
+      com.docker.network.driver.mtu: 9000
+  macvlan_net:
+    driver: macvlan
+    driver_opts:
+      mode: bridge
+    ipam:
+      config:
+        -
+          subnet: 192.168.20.0/24
+          gateway: 192.168.20.1

test/compose/update_network_mtu/tests.sh

@@ -0,0 +1,10 @@
+# -*- bash -*-
+
+podman network inspect --format='{{ range . }} {{ .Options.mtu }} {{ end }}' update_network_mtu_default
+like "$output" "9000" "$testname : network mtu is set"
+
+podman network inspect --format='{{ range . }} {{ .NetworkInterface }} {{ end }}' update_network_mtu_default
+like "$output" "docker0" "$testname: network interface is set"
+
+podman network inspect --format='{{ range . }} {{ .Options.mode }} {{ end }}' update_network_mtu_macvlan_net
+like "$output" "bridge" "$testname : network mode is set"