feat: add refresh_*_with_options for parsing with timeout

[rmehri01]

Adds refresh_from_buffer_with_options and refresh_from_string_with_options which support a timeout.

Some small cleanups:

• Remove syntax: *Self from refresh_from_buffer since it isn't being used.
• Remove sentinel requirement from refresh_from_string since I don't think it is needed anywhere.
• Implement refresh_from_string in terms of refresh_from_buffer since they are almost identical.

Note I haven't tested this with flow yet since it doesn't compile on 0.17-dev.

Closes #22