Fix broken Cookie Jar documentation examples (#18573).

• HttpCookie.new('name', 1) raised TypeError because the constructor passed non string values directly to HTTP::Cookie.new. Now converts to string via to_s.

• Updated wiki examples to include required domain and path keyword arguments and use string values.

Verification

• Start msfconsole and run irb
• Run Msf::Exploit::Remote::HTTP::HttpCookie.new('test', 1). Verify no error, value is "1"
• Run cj = Msf::Exploit::Remote::HTTP::HttpCookieJar.new
• Run cj.add(Msf::Exploit::Remote::HTTP::HttpCookie.new('test', 'val', domain: 'example.com', path: '/')). Verify no error
• Run cj.cookies. Verify cookie is present