Save pickled function as AiiDA node

[superstar54]

Fix issue #382 .

• do not pickle the function when decorating the function using task
• Only save it using PickledFunction data when launch the WorkGraph

@task.calcfunction()
def add(x, y):
    return x + y

@task.calcfunction()
def multiply(x, y):
    return x * y

wg = WorkGraph("add_multiply_workflow")
add_task = wg.add_task(add, name="add1", x=orm.Int(2), y=orm.Int(3))
wg.add_task(multiply, name="multiply1", x=add_task.outputs["result"], y=orm.Int(4))
wg.submit(wait=True)

The PickledFunction data will be the inputs of the WorkGraph, as shown below:

$ verdi process show 22462
Property     Value
-----------  ------------------------------------
type         WorkGraph<add_multiply_workflow>
state        Finished [0]
pk           22462
uuid         e79aac27-4065-4bc5-b199-8622bcdb045d
label        add_multiply_workflow
description
ctime        2024-12-05 21:34:27.117931+00:00
mtime        2024-12-05 21:34:30.034747+00:00

Inputs                         PK     Type
-----------------------------  -----  ---------------
wg
    tasks
        add1
            inputs
                x
                    property
                        value  22459  Int
                y
                    property
                        value  22460  Int
            executor
                callable       22457  PickledFunction
        multiply1
            inputs
                y
                    property
                        value  22461  Int
            executor
                callable       22458  PickledFunction

Outputs             PK  Type
---------------  -----  ------
execution_count  22467  Int

Called        PK  Type
---------  -----  --------
add1       22463  add
multiply1  22465  multiply

Log messages
----------------------------------------------
There are 11 log messages for this calculation
Run 'verdi process report 22462' to see them

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 98.40000% with 2 lines in your changes missing coverage. Please review.

Project coverage is 91.00%. Comparing base (c08af7a) to head (6b86b4c).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/aiida_workgraph/orm/pickled_function.py	0.00%	1 Missing ⚠️
src/aiida_workgraph/utils/__init__.py	95.45%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #383      +/-   ##
==========================================
+ Coverage   90.82%   91.00%   +0.17%     
==========================================
  Files          64       65       +1     
  Lines        4601     4648      +47     
==========================================
+ Hits         4179     4230      +51     
+ Misses        422      418       -4     

Flag	Coverage Δ
python-3.11	90.96% <98.40%> (+0.17%)	⬆️
python-3.12	90.96% <98.40%> (+0.17%)	⬆️
python-3.9	91.00% <98.40%> (+0.17%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.