Improve handling of sqlite:// in-memory performance trick

[dr-rodriguez]

Some of the implementations have been using the ability to connect to an in-memory sqlite database to improve on performance. This is particularly notable for Windows systems.
However, the in-memory database does not yet function with Felis. Some code changes are needed to take the Felis path and pass it along so that the in-memory database will also have that schema.

Likely the easiest change is to add felis_schema as an optional parameter in astrodb.Database to specify the path to the Felis schema and then pass that along to create_database when the in-memory database is being created.

[dr-rodriguez]

For the record, this was the old procedure:

db = Database(
    "sqlite://", reference_tables=reference_tables
)  # creates and connects to a temporary in-memory database
db.load_database(
    data_path
)  # loads the data from the data files into the database
db.dump_sqlite(db_file)  # dump in-memory database to file
db = Database(
    db_connection_string, reference_tables=reference_tables
)  # replace database object with new file version

and the problem is the implicit DB creation that is happening in the first step.