56 oracle db integration (#280)

* oraclevs custom

ingestion & retrieval with content rerefence only in vectorstore to the original text content in a field table

* fix chunk order by distance

* GUI to get SQL/DB Connection

one shot vector store ingestion from a SQL query

* SQL query support for VARCHAR fields

* fix after merge

* pylint

* pylint

* pylint fixes

* pylint fix

* demo move under doc/demo

* fix error messages and db connection handling

---------

Co-authored-by: John Lathouwers <[email protected]>

Author: corradodebari

docs/demo/README.md

@@ -0,0 +1,5 @@
+## Demo: OracleVS extension for no data duplication in vectorstore
+
+Demo to show an *experimental* implementation of a "referenced" vectorstore, coming by a relational table data source.
+
+Run the Jupyter Notepad `oraclevs_new.ipynb` and follow the instructions and explanation there.