Add tags to plays

Adds various tags to the deploy_steps_playbook output.

- facts: Run fact gathering
- overcloud: Run all plays for overcloud deployment
- pre_deploy_steps: Run deployments that happen pre deploy_steps
- host_prep_steps: Run host_prep_tasks
- deploy_steps: Run deploy_steps
- post_deploy_steps: Run deployments that happen post deploy_steps
- external: Run all external deployments
- external_deploy_steps: Run all external deployments

external and external_deploy_steps are the same for now. However, I kept
them both b/c "external" is the parallel for "overcloud", and
"external_deploy_steps" is the parallel for "deploy_steps".

Also fixes the name of the host_prep_tasks play that was incorrectly
named "Deployment steps".

Change-Id: Ic6579d187035d00edc1f9190f8ebd12d4400d919

common/deploy-steps.j2

@@ -358,9 +358,13 @@ outputs:
               name: Gather facts undercloud
               gather_facts: yes
               become: false
+              tags:
+                - facts
             - hosts: overcloud
               name: Gather facts overcloud
               gather_facts: yes
+              tags:
+                - facts
             - hosts: overcloud
               name: Server deployments
               gather_facts: no
@@ -373,8 +377,11 @@ outputs:
                   when: role_name == '{{role.name}}'
                   with_items: "{{ '{{' }} {{role.name}}_pre_deployments|default([]) {{ '}}' }}"
 {%- endfor %}
+              tags:
+                - overcloud
+                - pre_deploy_steps
             - hosts: overcloud
-              name: Deployment steps
+              name: Host prep steps
               gather_facts: no
               any_errors_fatal: yes
               vars:
@@ -384,6 +391,9 @@ outputs:
                 - include: {{role.name}}/host_prep_tasks.yaml
                   when: role_name == '{{role.name}}'
 {%- endfor %}
+              tags:
+                - overcloud
+                - host_prep_steps
 {%- for step in range(1,deploy_steps_max) %}
             - hosts: undercloud
               name: External deployment step {{step}}
@@ -394,6 +404,9 @@ outputs:
                 step: '{{step}}'
               tasks:
                 - include: external_deploy_steps_tasks.yaml
+              tags:
+                - external
+                - external_deploy_steps
             - hosts: overcloud
               name: Overcloud deployment step {{step}}
               gather_facts: no
@@ -403,6 +416,9 @@ outputs:
                 step: '{{step}}'
               tasks:
                 - include: deploy_steps_tasks.yaml
+              tags:
+                - overcloud
+                - deploy_steps
 {%- endfor %}
             - hosts: overcloud
               name: Server Post Deployments
@@ -415,6 +431,9 @@ outputs:
                     force: false
                   when: role_name == '{{role.name}}'
                   with_items: "{{ '{{' }} {{role.name}}_post_deployments|default([]) {{ '}}' }}"
+              tags:
+                - overcloud
+                - post_deploy_steps
 {%- endfor %}
       external_deploy_steps_tasks: {get_attr: [ExternalDeployTasks, value]}
       update_steps_tasks: |