feat : HEXA-1124 button to create a new pipeline from a template

[YolanFery]

GraphQL endpoint to create a new pipeline from a template

Changes

• Endpoint and model method to create a pipeline
• Add source_template to pipeline to keep a reference of the template used to create this pipeline
• Unit test to cover creation of pipeline and duplicate creation of pipeline

How/what to test

Creating a pipeline from a template using GraphQL endpoint is working

[nazarfil]

Can you give more context about this comment? The (from Template) would be appended to the pipeline code and would break the parsing if we would reuse it as it.
So I would like to know if the expected flow is for the user to open the pipeline code and edit it, and the comment line will indicate that code is copied form template and has to be edited?
If the goal of it is to mark it as code form template then i would append it as a python comment "/n # (from Template)"

[YolanFery]

Thanks for raising this

The intent was to create a different name for the pipeline that is created but you are correct that it makes the code unparseable. In addition to mis-align the python code and the Database object (the @pipeline(code= , name= ) would need to be modified )

So, as part of #885, I am using the same name as the original Pipeline to avoid such complexity at this point