WL#2063: Remove Databuf from TC and LQH

Databuf is another entity used which is not really needed.
Attrbuf is used for a similar task and so Attrbuf should be used
for this purpose.

At the same Attrbuf should be using dynamic memory management as
in WL #1497

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My idea has always been that both AttrBuf and DataBuf should be removed.
And TCKEYREQ/LQHKEYREQ instead would use long signals,
then all attrinfo (and keyinfo) would be placed in long signal memory

(which should be made configurable)