QUIC: limited the number of client-initiated streams.

QUIC: limited the number of client-initiated streams.

The limits on active bidi and uni client streams are maintained at their
initial values initial_max_streams_bidi and initial_max_streams_uni by sending
a MAX_STREAMS frame upon each client stream closure.

Also, the following is changed for data arriving to non-existing streams:

- if a stream was already closed, such data is ignored
- when creating a new stream, all streams of the same type with lower ids are
  created too