Clang formatting of qt/clientmodel.cpp and test/net_tests.cpp

Summary: Clang formatting of qt/clientmodel.cpp and test/net_tests.cpp

Test Plan: cd src; clang-format -assume-filename=.clang-format qt/clientmodel.cpp and look for diff

Reviewers: freetrader, deadalnix, kyuupichan, awemany, #bitcoin_abc

Reviewed By: deadalnix, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D226