Add should_exit support for v2 parsers

- Add should_exit support to v2 platform parsers
- Introduce macros.h and integrate trait hints
- Wire CMake packaging with config, version, and install dirs
- Update parser traits to include validation hooks and fixes

src/headers/parser/parser_v2.hpp

@@ -3,7 +3,6 @@
 #include <argument_parser.hpp>
 #include <array>
 #include <cstdlib>
-#include <fake_parser.hpp>
 #include <initializer_list>
 #include <memory>
 #include <optional>
@@ -91,12 +90,14 @@ namespace argument_parser::v2 {
 		using argument_parser::base_parser::current_conventions;
 		using argument_parser::base_parser::reset_current_conventions;
 
-		void prepare_help_flag() {
+		void prepare_help_flag(bool should_exit = true) {
 			add_argument({{flags::ShortArgument, "h"},
 						  {flags::LongArgument, "help"},
-						  {flags::Action, helpers::make_non_parametered_action([this]() {
+						  {flags::Action, helpers::make_non_parametered_action([this, should_exit]() {
 							   this->display_help(this->current_conventions());
-							   std::exit(0);
+							   if (should_exit) {
+								   std::exit(0);
+							   }
 						   })},
 						  {flags::HelpText, "Prints this help text."}});
 		}