move all frame sending functionality into separate class (for future: may be don't use Frame class there, and just build final packet with frame, which will be sent to connection)
implement fragmentation in FrameSender.sendFragmented for request frames
implement simple reassembly logic in FrameHandler - TODO some improvements can be added here, like additional checking of consistency like in rsocket-java
minimal tests added for fragmentation and reassembly - TODO need to add more tests
TODO need to add more tests for leaked buffers in case of failures
NOTE: Depends on #176
Frameclass there, and just build final packet with frame, which will be sent to connection)FrameSender.sendFragmentedfor request framesFrameHandler- TODO some improvements can be added here, like additional checking of consistency like in rsocket-java