Allow number of settings per H2 session to be configurable

(cherry picked from commit d91a8ca17bb17b08ce7f040b868e3c286a7bb0a6)

 Conflicts:
	doc/admin-guide/files/records.config.en.rst
	mgmt/RecordsConfig.cc
	proxy/http2/HTTP2.cc
	proxy/http2/HTTP2.h
	proxy/http2/Http2ConnectionState.h
6 files changed