trim input to TGI, moved clustering and summarization to dataprep and store in DB

[rbrugaro]

Several enhancements:

1. trim input to TGI in cases where all community partial answers do not fit in the input context of the final answer generation -> this was causing error
2. In previous implementation clustering and summary extraction was done at query time resulting in slow time to fist token. Moved clustering a full dataset summariization to the dataprep step. In addition to storing the graph in Neo4j now we also store the entity_info and the community_summaries for retrieval with cypher queries in retriever code
3. fix gateway input

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
comps/cores/mega/gateway.py	0.00%	1 Missing ⚠️

Files with missing lines	Coverage Δ
comps/cores/mega/gateway.py	29.82% <0.00%> (ø)

[ashahba]

Thanks @rbrugaro for this PR.
My feedback should be pretty straight forward.
Most of questions about timeout's are just to bring them to your attention and it's your call to decide on the final default values.

[ashahba]

LGTM!