Warn users when a flag prefixed with -[-]kokkos is not recognized and do not remove it

[dalg24]

• Do not silently ignore flags we do not recognize when parsing command line arguments if they start with --kokkos or -kokkos
• Provide a function to tell Kokkos Core not to emit a warning for flags that match some user provided regular expression Impl::do_not_warn_not_recognized_command_line_argument. By default, we only exclude those starting with --kokkos-tool but we could expand later as needed.
• Fix bug: do not remove flags prefixed with --kokkos that were not actually handled

[dalg24]

PS: feel free to suggest a better name for the function

[lucbv]

I think that's fine, I like the use of regex

[dalg24]

Retest this please

[PhilMiller]

Suggested change

	remove_flag = std::string(argv[iarg]).find("--kokkos-") == 0;
	bool begins_with_kokkos = std::string(argv[iarg]).find("--kokkos-") == 0; // move up to top
	remove_flag = begins_with_kokkos;