Add support for parameter rename on ipahostgroup.

FreeIPA 4.8.7 introduced an option to rename an existing hostgroup.
This patch adds support for renaming hostgroups if the option is
available on installed IPA version.

A new state `renamed` and a new option `rename` (alias: `new_name`)
was added to module `ipahostgroup` to allow renaming of host groups.

The implemented behavior is:
* Rename if `name` exists and `rename` doesn't.
* Do nothing if `name` does not exist and `rename` does, or if
  `name` equals to `rename`. (result.changed is False)
* Fail if neither or both `name` and `rename` exist.

tests/hostgroup/test_hostgroup_rename.yml

@@ -0,0 +1,105 @@
+---
+- name: Test hostgroup
+  hosts: ipaserver
+  become: true
+  gather_facts: false
+
+  tasks:
+  - name: Ensure testing host-group are absent
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name:
+      - databases
+      - datalake
+      - inexistenthostgroup
+      state: absent
+
+  - name: Ensure host-group databases is present
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: databases
+      state: present
+    register: result
+    failed_when: not result.changed
+
+  - name: Rename host-group from `databases` to `datalake`
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: databases
+      rename: datalake
+      state: renamed
+    register: result
+    failed_when: not result.changed
+
+  - name: Ensure host-group database was already absent
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: database
+      state: absent
+    register: result
+    failed_when: result.changed
+
+  - name: Rename host-group from `databases` to `datalake`, again
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: databases
+      rename: datalake
+      state: renamed
+    register: result
+    failed_when: result.changed or result.failed
+
+  - name: Rename host-group with same name.
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: datalake
+      rename: datalake
+      state: renamed
+    register: result
+    failed_when: result.changed
+
+  - name: Ensure testing hostgroups do not exist.
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: inexistenthostgroup,alsoinexistent
+      state: absent
+
+  - name: Rename inexistent host-group to an existing one.
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: inexistenthostgroup
+      rename: datalake
+      state: renamed
+    register: result
+    failed_when: result.changed or result.failed
+
+  - name: Rename inexistent host-group to a non-existing one.
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: inexistenthostgroup
+      rename: alsoinexistent
+      state: renamed
+    register: result
+    failed_when: not result.failed or "Attribute `rename` can not be used, unless hostgroup exists." not in result.msg
+
+  - name: Ensure host-group databases is present
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: databases
+      state: present
+
+  - name: Rename host-group to an existing one.
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name: databases
+      rename: datalake
+      state: renamed
+    register: result
+    failed_when: not result.failed or "This entry already exists" not in result.msg
+
+  - name: Ensure host-group databases and datalake are absent
+    ipahostgroup:
+      ipaadmin_password: SomeADMINpassword
+      name:
+      - databases
+      - datalake
+      state: absent