[docker_network_facts] Creating docker_network_facts module (#49644)

Part of #49267

test/integration/targets/docker_network_facts/aliases

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+shippable/posix/group2
+skip/osx
+skip/freebsd
+destructive
+skip/rhel8.0

test/integration/targets/docker_network_facts/meta/main.yml

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+---
+dependencies:
+  - setup_docker

test/integration/targets/docker_network_facts/tasks/main.yml

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+---
+- block:
+  - name: Create random network name
+    set_fact:
+      nname: "{{ 'ansible-test-%0x' % ((2**32) | random) }}"
+
+  - name: Make sure network is not there
+    docker_network:
+      name: "{{ nname }}"
+      state: absent
+      force: yes
+
+  - name: Inspect a non-present network
+    docker_network_facts:
+      name: "{{ nname }}"
+    register: result
+
+  - assert:
+      that:
+      - "not result.exists"
+      - "'docker_network' in result"
+      - "result.docker_network is none"
+
+  - name: Make sure network exists
+    docker_network:
+      name: "{{ nname }}"
+      state: present
+
+  - name: Inspect a present network
+    docker_network_facts:
+      name: "{{ nname }}"
+    register: result
+  - name: Dump docker_network_facts result
+    debug: var=result
+
+  - name: "Comparison: use 'docker network inspect'"
+    command: docker network inspect "{{ nname }}"
+    register: docker_inspect
+  - set_fact:
+      docker_inspect_result: "{{ docker_inspect.stdout | from_json }}"
+  - name: Dump docker inspect result
+    debug: var=docker_inspect_result
+
+  - name: Cleanup
+    docker_network:
+      name: "{{ nname }}"
+      state: absent
+      force: yes
+
+  - assert:
+      that:
+      - result.exists
+      - "'docker_network' in result"
+      - "result.docker_network"
+      - "result.docker_network == docker_inspect_result[0]"
+
+  when: docker_py_version is version('1.8.0', '>=') and docker_api_version is version('1.21', '>=')
+
+- fail: msg="Too old docker / docker-py version to run docker_network_facts tests!"
+  when: not(docker_py_version is version('1.8.0', '>=') and docker_api_version is version('1.21', '>=')) and (ansible_distribution != 'CentOS' or ansible_distribution_major_version|int > 6)