A C-style cast is equivalent to try casting in the following order:

1. const_cast(...)
2. static_cast(...)
3. const_cast(static_cast(...))
4. reinterpret_cast(...)
5. const_cast(reinterpret_cast(...))

By using static_cast<T>(...) explicitly we avoid the possibility
of an unintentional and dangerous reinterpret_cast. Furthermore
static_cast<T>(...) allows for easier grepping of casts. Please enter the commit message for your changes. Lines starting

Backport of Core PR10498
https://github.com/bitcoin/bitcoin/pull/10498

Completes T555

make check
test_runner.py