Update GeneratePythonScript to support nested algorithm history

[Samuel Jackson]

The GeneratePythonScript needs to be updated to support nested algorithm history. This includes the ability to unroll the history to a desired level and to add better formatting to the generated scripts. For more details see the nested history design document:

​https://github.com/mantidproject/documents/blob/master/Design/Nested%20History%20Detailed%20Design%20Document.docx

[Samuel Jackson]

I've done this the other way round as generating a script from the GUI was a more complicated case and there's no easy way pass a parameter to unroll the history to different levels in a python script. Therefore, once the changes in #9369 pass, swap GeneratePythonScript to use the script building mechanism added in that ticket.

[Samuel Jackson]

Refs #9370 Swap algorithm to use ScriptBuilder.

Changeset: 4b5b5cae97d0254e707a729c2c4ab56f925b6dec

[Samuel Jackson]

Refs #9370 Update usage examples to match.

Changeset: 5077640b3d18ca81d63f94edb69d70b892b4dc57

[Samuel Jackson]

To Test

There's no simple way to support nested algorithm history from GeneratePythonScript. But I have provided an option to unroll all of the history which defaults to being off so you just get the top level algorithms as usual.

• Check the system/unit tests are passing.
• Check using GeneratePythonScript on a workspace will reproduce the history of the top levle algorithms
• Try the unroll all option on a workspace with a history with at least one Data Processor Algorithm in it and check you get all of the children output.

[Nick Draper]

Merge remote-tracking branch 'origin/feature/9370_generate_python_script_nested_history'

Full changeset: ​e1e1880c48751ccabcdef6a7fbe42e8bc295f32c

[Stuart Campbell]

This ticket has been transferred to github issue ​10213