fix: -Wunsafe-buffer-usage warnings in IsUrlArg() (#43541)

* fix: -Wunsafe-buffer-usage warnings in IsUrlArg()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* chore: improve code comments for CheckCommandLineArguments()

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* chore: reduce diffs from main

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* refactor: CheckCommandLineArguments takes a StringVector arg

Fixes another buffer warning!

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* chore: use base::CommandLine::StringPieceType

base:CommandLine::StringViewType has not been invented yet

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>