proxy/handler: tweak arg handling style and format

[jkarneges]

This does a few small things:

• Use tabs instead of spaces in C++ source files.
• Ensure files end with a newline.
• Remove some errant whitespace.
• Drop get prefix from getters.
• Mark test functions static.
• Some #include block reordering/simplifying.
• Update the args structs a little bit, such as adding verbose fields, and changing Option<Vec<String>> to Vec<String> which clap still counts as optional.