Removed all usages of boost::assign::list_of in favor of C++11 initializer lists

Summary: C++11 initializer lists are more elegant and easier to maintain and read. So I removed all usages of boost::assign::list_of in favor of them. Note that some of these files have never been linted before so they may have extra lint formatting changes too.

Test Plan: make check, rpc-tests.py

Reviewers: freetrader, deadalnix, #bitcoin_abc, ealmansi

Reviewed By: freetrader, deadalnix, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D465