### Apache Airflow version

2.3.3 (latest released)

### What happened

An URL I saved in the past, `https://astronomer.astronomer.run/dx4o2568/home?tags=test`,  has the tag field in the query parameter though I was not aware of this. When I clicked on the URL, I was confused because I did not see any DAGs when I should have a bunch.

After closer inspection, I realized that the URL has the tag field in the query parameter but then noticed that the tag box in the Airflow UI wasn't properly populated.

![screen_shot_2022-07-12_at_8 11 07_am](https://user-images.githubusercontent.com/5952735/182496710-601b4a98-aacb-4482-bb9f-bb3fdf9e265f.png)


### What you think should happen instead

When I clicked on the URL, the tag box should have been populated with the strings in the URL.

### How to reproduce

Start an Airflow deployment with some DAGs and add the tag query parameter. More specifically, it has to be a tag that is not used by any DAG.

### Operating System

N/A

### Versions of Apache Airflow Providers

_No response_

### Deployment

Astronomer

### Deployment details

_No response_

### Anything else

_No response_

### Are you willing to submit PR?

- [X] Yes I am willing to submit a PR!

### Code of Conduct

- [X] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)

selected_dag_ids = {unquote(dag_id) for dag_id in request.form.getlist("dag_ids") if dag_id}
        if selected_dag_ids:
            filter_dag_ids = selected_dag_ids.intersection(allowed_dag_ids)
        else:
            filter_dag_ids = allowed_dag_ids
        if not filter_dag_ids:
            return flask.json.jsonify({})
        payload = {}
        dag_state_stats = dag_state_stats.filter(dr.dag_id.in_(filter_dag_ids))
        data = {}
        for dag_id, state, count in dag_state_stats:
            if dag_id not in data:
                data[dag_id] = {}
            data[dag_id][state] = count
        for dag_id in filter_dag_ids:
            payload[dag_id] = []
            for state in State.dag_states:
                count = data.get(dag_id, {}).get(state, 0)
                payload[dag_id].append({"state": state, "count": count})
        return flask.json.jsonify(payload)
    @expose("/task_stats", methods=["POST"])
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
        ]
    )
    @provide_session
    def task_stats(self, session=None):