[FLINK-6476] - Table environment register row data stream

[rtudoran]

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[rtudoran]

@fhueske

Please have a look. I inserted tests in scala and java to check the registration of the stream.
For scala - it seemed to work directly if the implicit value is set (i did not know to test this before opening the JIRA).
For java - i have added the needed support in TableEnvironment.

it is not much...i hope i did not miss anything

(I closed the previous PR as by mistake i pushed also an intermediate commit )