Use brace initialization instead of copy initialization

[krishnakumarg1984]

@mmcleod89 Let us systematically replace all uses of C-style copy initialisations with uniform brace initialisation. This is a best practice that will prevent narrowing conversions.

See this C++ core guideline here for more explanation from Stroustrup: https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#Res-list