python: Remove `TaintStepFromSummary`

[yoff]

trafficstars

as it should be covered by SummarizedCallableFromModel

Also move things around, to look more like the Ruby code.

Thanks to @aschackmull for finding this.

[yoff]

So the test reveal that we lose some results by this. Specifically, we lose support for the Argument[n..] syntax. This is supported via getNodeFromInputOutputPath in ApiGraphModelsSpecific, we follow Javascript here and end up calling parseIntWithArity from the shared library. I have made this a draft until I can investigate what we need to add in order for summarized callables to support this syntax also.

[yoff]

So the test reveal that we lose some results by this. Specifically, we lose support for the Argument[n..] syntax. This is supported via getNodeFromInputOutputPath in ApiGraphModelsSpecific, we follow Javascript here and end up calling parseIntWithArity from the shared library. I have made this a draft until I can investigate what we need to add in order for summarized callables to support this syntax also.

So what we need is to make Argument[n..] a parameter position as in Ruby. I do not immediately see any unwanted consequences of doing this, let me know if you think of any..

[yoff]

Evaluation was uneventful. (Perhaps we could have seen some steps not being duplicated if I had turned on tuple counting..)