* Rename commands.exportifw.cpp -> export.ifw.cpp

* move DryRun from commands.h -> commands.interface.h

* move vcpkgcmdarguments and vcpkgpaths over to commands.interface.h

* move vcpkg::Commands::BuildExternal -> commands.buildexternal.h

* add commands.*.h for the commands.*.cpp

* move vcpkg::Commands::* to commands.*.h

* move vcpkg::Commands::{Hash,Fetch} to their own files

* change include commands.h -> commands.*.h in commands.*.cpp

* remove commands.*.h from commands.h

* join vcpkg::Commands::* into one namespace line

* fix vcxproj build