Create a version of MultimodalQnA example with Zilliz/Milvus as Vector DB

[codingjaguar]

Priori### Description

Create a version of MultimodalQnA example with Milvus as Vector DB

The implementation can reference this code example for the interaction with Milvus vector database: https://milvus.io/docs/multimodal_rag_with_milvus.md

#OPEAHack

[isaacncz]

/assignme

[srajabos]

OPEA_Team2 is working on this issue

[srajabos]

#1639