Add tag for service account.

##### SUMMARY
Currently, the process to add tags to Google Cloud service accounts using Ansible requires executing gcloud commands to manage tags. We propose a new feature to be added to the Google Collection for Ansible that would allow users to manage tags directly through an Ansible module.

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
gcp_iam_tag_service_account

##### ADDITIONAL INFORMATION
Check if a Tag Key Exists
Verify whether a specific tag key (e.g., InfrastructureProvider) exists for a given project.

Create a Tag Key
If the specified tag key does not exist, allow for its creation within a specified project with a description.

Check or Get Tag Value
Retrieve the tag value associated with a tag key if it exists, such as finding the value for shortName=.

Create a Tag Value
If the tag value does not exist under the tag key, enable its creation with a description.

Bind Tag to Service Account
Facilitate the binding of a specified tag value to a service account in a manner that permits flexible resource management and automation.

```yaml
- name: Check if InfrastructureProvider tag key exists
ansible.builtin.command: gcloud resource-manager tags keys list --parent=projects/ --filter="shortName=InfrastructureProvider" --format="value(name)"
register: tag_key_list
failed_when: false
changed_when: tag_key_list.rc != 0

- name: Display existing tag message
ansible.builtin.debug:
msg: "TagKey 'InfrastructureProvider' already exists."
when: tag_key_list.stdout != ""

- name: Get the tag value name where shortName is
ansible.builtin.command: gcloud resource-manager tags values list --parent=tagKeys/ --filter="shortName=" --format="value(name)"
register: tag_value_list
failed_when: false
changed_when: tag_value_list.rc != 0
when: tag_key_list.stdout != ""

- name: Set tagValues name if tag key exists
ansible.builtin.set_fact:
tag_value_name: "{{ tag_value_list.stdout }}"
when: tag_key_list.stdout != ""

- name: Create InfrastructureProvider tag if it doesn't exist
ansible.builtin.command: gcloud resource-manager tags keys create InfrastructureProvider --parent=projects/ --description="InfrastructureProvider tag"
register: tag_key_create
when: tag_key_list.stdout == ""
changed_when: tag_key_create.rc != 0

- name: Set tagKeys value
ansible.builtin.set_fact:
tag_key_name: "{{ item.split(': ')[1] }}"
loop: "{{ tag_key_create.stdout_lines | d([]) }}"
when:
- "'tagKeys' in item"
- tag_key_list.stdout == ""

- name: Create InfrastructureProvider tag value
ansible.builtin.command: gcloud resource-manager tags values create "" --parent={{ tag_key_name }} --description="InfrastructureProvider tag value"
register: tag_value_create
when: tag_key_list.stdout == ""
changed_when: tag_value_create.rc != 0

- name: Set tagValues value
ansible.builtin.set_fact:
tag_value_name: "{{ item.split(': ')[1] }}"
loop: "{{ tag_value_create.stdout_lines | d([]) }}"
when:
- "'tagValues' in item"
- tag_value_create.stdout_lines is defined

- name: Bind InfrastructureProvider tag to infra service account
ansible.builtin.command: 'gcloud resource-manager tags bindings create --tag-value={{ tag_value_name }} --parent=//iam.googleapis.com/projects/{{ customer_cloud_provider.account_data.gcp_project }}/serviceAccounts/infra-{{ service_account_email }}'
register: infra_bind_output
#when: tag_key_list.stdout == ""
changed_when: infra_bind_output.rc != 0
```

Start with the proposed gcp_iam_tag_service_account component and review the Google Cloud tag key, tag value, and service-account binding operations shown in the issue. Define the module's behavior for checking or creating keys and values, then binding the selected value to the service account. Done means these steps are manageable without gcloud commands and the module reports appropriate changes and existing resources.

Written by the indexing model from the issue text.