In reality, we only want to model this as a `rest_framework.response.Response`, since our .qll modeling is more precise for rest-framework responses than if we also modeled it as a basic django http response. (specifically, that default mime-type handling is way different).
mostly removing of nodes from the graph.
One result lost:
```
check("submodule.submodule_attr", submodule.submodule_attr, "submodule_attr", globals()) #$ MISSING:prints=submodule_attr
```
I fixed it in both predicates... I think we might still be able to remove
`newDirectAlias` -- but with it being better, it will allow us to better test if `newImportAlias` actually cover everything we need!
Due to the 'only model most specific spec' logic highlighted in previous
commit, I'm changing away from MethodView/View, and use Django view instead.
In practice this shouldn't matter at all, but for writing tests it would
have been a nice fix to only have the "same name but more specific"
logic apply when it's the same _definition_ location. We used to have
this information available, but right now we don't... so instead of
spending a lot of time rewriting the core library, I simply used a
different class :D :O :(
This commit removes SSA nodes from the data flow graph. Specifically, for a definition and use such as
```python
x = expr
y = x + 2
```
we used to have flow from `expr` to an SSA variable representing x and from that SSA variable to the use of `x` in the definition of `y`. Now we instead have flow from `expr` to the control flow node for `x` at line 1 and from there to the control flow node for `x` at line 2.
Specific changes:
- `EssaNode` from the data flow layer no longer exists.
- Several glue steps between `EssaNode`s and `CfgNode`s have been deleted.
- Entry nodes are now admitted as `CfgNodes` in the data flow layer (they were filtered out before).
- Entry nodes now have a new `toString` taking into account that the module name may be ambigous.
- Some tests have been rewritten to accomodate the changes, but only `python/ql/test/experimental/dataflow/basic/maximalFlowsConfig.qll` should have semantic changes.
- Comments have been updated
- Test output has been updated, but apart from `python/ql/test/experimental/dataflow/basic/maximalFlows.expected` only `python/ql/test/experimental/dataflow/typetracking-summaries/summaries.py` should have a semantic change. This is a bonus fix, probably meaning that something was never connected up correctly.
Factor out use-use flow in order to do this.
Also improve names and comments.
I also wanted to change the types in `difinitionFlowStep`, but
that broke the module instantiation.
