### 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)

"""
    BigQueryInsertJobTrigger run on the trigger worker to perform insert operation
    :param conn_id: Reference to google cloud connection id
    :param job_id:  The ID of the job. It will be suffixed with hash of job configuration
    :param project_id: Google Cloud Project where the job is running
    :param dataset_id: The dataset ID of the requested table. (templated)
    :param table_id: The table ID of the requested table. (templated)
    :param poll_interval: polling period in seconds to check for the status
    """
    def __init__(
        self,
        conn_id: str,
        job_id: str | None,
        project_id: str | None,
        dataset_id: str | None = None,
        table_id: str | None = None,
        poll_interval: float = 4.0,
    ):
        super().__init__()
        self.log.info("Using the connection  %s .", conn_id)
        self.conn_id = conn_id
        self.job_id = job_id
        self._job_conn = None
        self.dataset_id = dataset_id
        self.project_id = project_id
        self.table_id = table_id
        self.poll_interval = poll_interval
    def serialize(self) -> tuple[str, dict[str, Any]]: