expose a couple of specific sqlite3 error codes to Class object (#18)

Co-authored-by: tmcguinness <terry.mcguinness@noaa.gov>

src/wxflow/sqlitedb.py

@@ -4,6 +4,14 @@
 __all__ = ["SQLiteDB"]
 
 
+class SQLiteDBError(Exception):
+    """
+    Base class for SQLiteDB exceptions.
+    """
+    OperationalError = sqlite3.OperationalError
+    IntegrityError = sqlite3.IntegrityError
+
+
 class SQLiteDB:
     """
     A class for interacting with an SQLite3 database.
@@ -17,6 +25,8 @@ class SQLiteDB:
 
     """
 
+    Error = SQLiteDBError
+
     def __init__(self, db_name: str) -> None:
         self.db_name = db_name
         self.connection: Optional[sqlite3.Connection] = None