Reland "[llvm-ir2vec] Adding Inst Embeddings Map API to ir2vec python bindings (#180140)" (#184196)
Relanding change from https://github.com/llvm/llvm-project/pull/180140
- Returns a Inst Embedding Map based on the input function name
`getInstEmbMap(funcName) -> Map<Inst string, Embedding>`
- Refactors IR2VecTool methods to have a separate call to create the
embedder object