Refactor of consul modules (#7826)

* Extract common functionality.

* Refactor duplicated code into module_utils.

* Fixed ansible-test issues.

* Address review comments.

* Revert changes to consul_acl.

It uses deprecated APIs disabled since Consul 1.11 (which is EOL), don't
bother updating the module anymore.

* Remove unused code.

* Merge token into default doc fragment.

* JSON all the way down.

* extract validation tests into custom file and prep for requests removal.

* Removed dependency on requests.

* Initial test for consul_kv.

* fixup license headers.

* Revert changes to consul.py since it utilizes python-consul.

* Disable the lookup test for now.

* Fix python 2.7 support.

* Address review comments.

* Address review comments.

* Addec changelog fragment.

* Mark ConsulModule as private.

tests/integration/targets/consul/tasks/consul_general.yml

@@ -0,0 +1,76 @@
+---
+# Copyright (c) Ansible Project
+# GNU General Public License v3.0+ (see LICENSES/GPL-3.0-or-later.txt or https://www.gnu.org/licenses/gpl-3.0.txt)
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+- name: ensure unknown scheme fails
+  consul_session:
+    state: info
+    id: dummy
+    scheme: non_existent
+    token: "{{ consul_management_token }}"
+  register: result
+  ignore_errors: true
+
+- assert:
+    that:
+      - result is failed
+
+- name: ensure SSL certificate is checked
+  consul_session:
+    state: info
+    id: dummy
+    port: 8501
+    scheme: https
+    token: "{{ consul_management_token }}"
+  register: result
+  ignore_errors: true
+
+- name: previous task should fail since certificate is not known
+  assert:
+    that:
+      - result is failed
+      - "'certificate verify failed' in result.msg"
+
+- name: ensure SSL certificate isn't checked when validate_certs is disabled
+  consul_session:
+    state: info
+    id: dummy
+    port: 8501
+    scheme: https
+    token: "{{ consul_management_token }}"
+    validate_certs: false
+  register: result
+
+- name: previous task should succeed since certificate isn't checked
+  assert:
+    that:
+      - result is changed
+
+- name: ensure a secure connection is possible
+  consul_session:
+    state: info
+    id: dummy
+    port: 8501
+    scheme: https
+    token: "{{ consul_management_token }}"
+    ca_path: '{{ remote_dir }}/cert.pem'
+  register: result
+
+- assert:
+    that:
+      - result is changed
+
+- name: ensure connection errors are handled properly
+  consul_session:
+    state: info
+    id: dummy
+    token: "{{ consul_management_token }}"
+    port: 1234
+  register: result
+  ignore_errors: true
+
+- assert:
+    that:
+      - result is failed
+      - result.msg.startswith('Could not connect to consul agent at localhost:1234, error was')