- remove `tupleStoreStep` and `dictStoreStep` from `containerStep`
These are imprecise compared to the content being precise.
- add implicit reads to recover taint at sinks
- add implicit read steps for decoders
to supplement the `AdditionalTaintStep`
that now only covers when the full container is tainted.
Mostly to highlight that with flow-summary modeling, we don't expect
taint for a lot of these.
I aslo opted to make `finditer()` tainted for consistency.