Load task definition inclusion

[yoavkt]

In this PR we added the ability to include a list of symbols for the tasks.

[edenjenzohar]

One small comment

[edenjenzohar]

This very hard to understand with the double negative logic. lets do:

if exclude_symbols: 
if include_symbols:

[yoavkt]

The issue that include_symbols could be a series:

import pandas as pd
a = None 
b = [1,2,3]
c = pd.Series(b)
if a:
    print("None is False")
if b:
    print("b is a list ")
if c:
    print("series is error ")

will yield

---------------------------------------------------------------------------
ValueError                                Traceback (most recent call last)
/var/folders/xb/f1xjztvd437bvj2g25bkbq3h0000gn/T/ipykernel_19828/782548513.py in ?()
      5 if a:
      6     print("None is False")
      7 if b:
      8     print("b is a list ")
----> 9 if c:
     10     print("series is error ")

/opt/miniconda3/envs/bmfm/lib/python3.10/site-packages/pandas/core/generic.py in ?(self)
   1574     @final
   1575     def __nonzero__(self) -> NoReturn:
-> 1576         raise ValueError(
   1577             f"The truth value of a {type(self).__name__} is ambiguous. "
   1578             "Use a.empty, a.bool(), a.item(), a.any() or a.all()."
   1579         )

ValueError: The truth value of a Series is ambiguous. Use a.empty, a.bool(), a.item(), a.any() or a.all().

We can check it with is instance do you think it will be better?

Something like

from collections.abc import Iterable
if isinstance(the_element, Iterable):