Database.query: use DataClassRowFactory + AttrDict

[pydanny]

https://rogerbinns.github.io/apsw/example.html#accessing-results-by-column-name

Right now we return a generator of dictionaries, we want to change to using AttrDict to improve the UI. In essence allowing this behavior:

for row in db.table.query(stmt):
    print(row['title']) # <-- Current
    print(row.title) # <-- What we want to add

Code implementation

As determined from discovery in #7, convert this:

class Database
    def query(
        self, sql: str, params: Optional[Union[Iterable, dict]] = None
    ) -> Generator[dict, None, None]:
        """
        Execute ``sql`` and return an iterable of dictionaries representing each row.

        :param sql: SQL query to execute
        :param params: Parameters to use in that query - an iterable for ``where id = ?``
          parameters, or a dictionary for ``where id = :id``
        """
        cursor = self.execute(sql, tuple(params or tuple()))
        try: columns = [c[0] for c in cursor.description]
        except apsw.ExecutionCompleteError: return []
        for row in cursor:
            yield dict(zip(columns, row))

to:

class Database:
    def query(
        self, sql: str, params: Optional[Union[Iterable, dict]] = None
    ) -> Generator[dict, None, None]:
        cursor = self.execute(sql, tuple(params or tuple()))
        # Row results will be dataclasses
        cursor.row_trace = apsw.ext.DataClassRowFactory(
            dataclass_kwargs={"frozen": True}
        )                
        # Yield attrdict so rows can be accessed as row.id or row['id']
        for row in cursor: yield AttrDict(row.__dict__)        
        # Cleanup the row_trace
        cursor.row_trace = None