### Apache Airflow version

main (development)

### What happened

1. When not providing `project_id` to `BigQueryGetDataOperator` in deferrable mode (`project_id=None`), the query generated by `generate_query` method is bugged, i.e.,: 

````sql
from `None.DATASET.TABLE_ID` limit ...
````

2. `as_dict` param does not work `BigQueryGetDataOperator`.

### What you think should happen instead

1. When `project_id` is `None` - it should be removed from the query along with the trailing dot, i.e.,:

````sql
from `DATASET.TABLE_ID` limit ...
````

2. `as_dict` should be added to the serialization method of `BigQueryGetDataTrigger`.

### How to reproduce

1. Create a DAG file with `BigQueryGetDataOperator` defined as follows:
```python
BigQueryGetDataOperator(
        task_id="bq_get_data_op",
        # project_id="PROJECT_ID",  <-- Not provided
        dataset_id="DATASET",
        table_id="TABLE",
        use_legacy_sql=False,
        deferrable=True
    )
````

2. 1. Create a DAG file with `BigQueryGetDataOperator` defined as follows:
```python
BigQueryGetDataOperator(
        task_id="bq_get_data_op",
        project_id="PROJECT_ID",
        dataset_id="DATASET",
        table_id="TABLE",
        use_legacy_sql=False,
        deferrable=True,
        as_dict=True
    )
````

### Operating System

Debian

### Versions of Apache Airflow Providers

_No response_

### Deployment

Official Apache Airflow Helm Chart

### Deployment details

_No response_

### Anything else

The `generate_query` method is not unit tested (which would have prevented it in the first place) - will be better to add one.

### 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)

"""
    Executes a BigQuery job. Waits for the job to complete and returns job id.
    This operator work in the following way:
    - it calculates a unique hash of the job using job's configuration or uuid if ``force_rerun`` is True
    - creates ``job_id`` in form of
        ``[provided_job_id | airflow_{dag_id}_{task_id}_{exec_date}]_{uniqueness_suffix}``
    - submits a BigQuery job using the ``job_id``
    - if job with given id already exists then it tries to reattach to the job if its not done and its
        state is in ``reattach_states``. If the job is done the operator will raise ``AirflowException``.
    Using ``force_rerun`` will submit a new job every time without attaching to already existing ones.
    For job definition see here:
        https://cloud.google.com/bigquery/docs/reference/v2/jobs
    .. seealso::
        For more information on how to use this operator, take a look at the guide:
        :ref:`howto/operator:BigQueryInsertJobOperator`
    :param configuration: The configuration parameter maps directly to BigQuery's
        configuration field in the job object. For more details see
        https://cloud.google.com/bigquery/docs/reference/v2/jobs
    :param job_id: The ID of the job. It will be suffixed with hash of job configuration
        unless ``force_rerun`` is True.
        The ID must contain only letters (a-z, A-Z), numbers (0-9), underscores (_), or
        dashes (-). The maximum length is 1,024 characters. If not provided then uuid will
        be generated.
    :param force_rerun: If True then operator will use hash of uuid as job id suffix
    :param reattach_states: Set of BigQuery job's states in case of which we should reattach
        to the job. Should be other than final states.
    :param project_id: Google Cloud Project where the job is running
    :param location: location the job is running