Print error message when reverting VM snapshot failed

[keirazhang]

We need to capture the error message while reverting VM snapshot failed, and print it into failed_tasks.log.

TASK [Display revert snapshot result] **************************************************************************************************************************************
task path: /home/qiz/workspace/github/ansible-vsphere-gos-validation/common/vm_revert_snapshot.yml:29
ok: [localhost] => {
    "revert_result": {
        "changed": false,
        "failed": true,
        "msg": "The operation cannot be allowed at the current time because the virtual machine has a question pending: \n 'msg.hbacommon.outofspace:There is no more space for virtual disk 'Ansible_winsrv_vbs_80ga-000003.vmdk'. You might be able to continue this session by freeing disk space on the relevant volume, and clicking Retry. Click Cancel to terminate this session.\n'."
    }
}

TASK [Initialize the fact whether there is snapshot not-exist error] *******************************************************************************************************
task path: /home/qiz/workspace/github/ansible-vsphere-gos-validation/common/vm_revert_snapshot.yml:33
ok: [localhost] => {
    "ansible_facts": {
        "snapshot_not_exists_error": false
    },
    "changed": false
}

TASK [Check there is error message about snasphot not existing] ************************************************************************************************************
task path: /home/qiz/workspace/github/ansible-vsphere-gos-validation/common/vm_revert_snapshot.yml:43
ok: [localhost] => {
    "ansible_facts": {
        "snapshot_not_exists_error": false
    },
    "changed": false
}

TASK [Failed to revert snapshot to BaseSnapshot] ***************************************************************************************************************************
task path: /home/qiz/workspace/github/ansible-vsphere-gos-validation/common/vm_revert_snapshot.yml:59
fatal: [localhost]: FAILED! => {
    "changed": false,
    "msg": "Failed to revert to snapshot 'BaseSnapshot' because of error: The operation cannot be allowed at the current time because the virtual machine has a question pending: \n 'msg.hbacommon.outofspace:There is no more space for virtual disk 'Ansible_winsrv_vbs_80ga-000003.vmdk'. You might be able to continue this session by freeing disk space on the relevant volume, and clicking Retry. Click Cancel to terminate this session.\n'."
}

[keirazhang]

When VM doesn't have any snapshot, the revert_result is:

2023-08-18 10:58:46,018 | TASK [test_debug][Display revert snapshot result] **********
task path: /home/qiz/workspace/github/ansible-vsphere-gos-validation/common/vm_revert_snapshot.yml:29
ok: [localhost] => {
    "revert_result": {
        "changed": false,
        "failed": true,
        "msg": "virtual machine - qiz-test-ide does not have any snapshots to revert to."
    }   
}

When VM has snapshot(s) but doesn't have the snapshot to revert, the revert_result is:

2023-08-18 10:05:15,018 | TASK [test_debug][Display revert snapshot result] **********
task path: /home/qiz/workspace/github/ansible-vsphere-gos-validation/common/vm_revert_snapshot.yml:29
ok: [localhost] => {
    "revert_result": {
        "changed": false,
        "failed": false,
        "msg": "Couldn't find any snapshots with specified name: test_snapshot on VM: qiz-test-ide"
    }   
}

[123lzxm]

LGTM, thanks.