Add tests for SqlAlchemy modeling library

After researching SqlAlchemy and it's various query methods, I discovered several types of SQL injection possibilities.

The SQLExecution.py file contains these examples and can be broken up into two types of injections. Injections requiring the text() taint-step and injections NOT requiring the text() taint step.

Author: mrthankyou

python/ql/test/experimental/library-tests/frameworks/sqlalchemy/ConceptsTest.ql

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+import python
+import experimental.meta.ConceptsTest

python/ql/test/experimental/library-tests/frameworks/sqlalchemy/SqlExecution.py

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+import sqlalchemy
+from sqlalchemy import Column, Integer, String, ForeignKey, create_engine
+from sqlalchemy.ext.declarative import declarative_base
+from sqlalchemy.pool import StaticPool
+from sqlalchemy.orm import relationship, backref, sessionmaker, joinedload
+from sqlalchemy.sql import text
+
+engine = create_engine(
+    'sqlite:///:memory:',
+    echo=True,
+    connect_args={"check_same_thread": False},
+    poolclass=StaticPool
+)
+
+Base = declarative_base()
+
+class User(Base):
+    __tablename__ = 'users'
+
+    id = Column(Integer, primary_key=True)
+    name = Column(String)
+
+Base.metadata.create_all(engine)
+
+Session = sessionmaker(bind=engine)
+session = Session()
+
+ed_user = User(name='ed')
+ed_user2 = User(name='george')
+
+session.add(ed_user)
+session.add(ed_user2)
+
+session.commit()
+
+# Injection without requiring the text() taint-step
+session.query(User).filter_by(name="some sql")  # $getSql="some sql"
+session.scalar("some sql")  # $getSql="some sql"
+engine.scalar("some sql")  # $getSql="some sql"
+session.execute("some sql")  # $getSql="some sql"
+
+with engine.connect() as connection:
+    connection.execute("some sql")  # $getSql="some sql"
+
+with engine.begin() as connection:
+    connection.execute("some sql")  # $getSql="some sql"
+
+# Injection requiring the text() taint-step
+session.query(User).filter(text("some sql"))  # $getSql="some sql"
+session.query(User).group_by( User.id ).having(text("some sql"))  # $getSql="some sql"
+session.query(User).group_by(text("name='some sql'")).first()  # $getSql="some sql"
+session.query(User).order_by(text("name='some sql'")).first()  # $getSql="some sql"
+
+query = select(User).where(User.name == text("some sql"))  # $getSql="some sql"
+with engine.connect() as conn:
+    conn.execute(query)