chore: remove unused clap dep and fix test_session_table name

- Remove clap dependency from retrieval-pipeline (RetrievalStrategy
  already has FromStr/Display; evaluations uses clap directly)
- Rename session table from test_session_table to session

retrieval-pipeline/Cargo.toml

@@ -21,9 +21,5 @@ async-openai = { workspace = true }
 async-trait = { workspace = true }
 uuid = { workspace = true }
 fastembed = { workspace = true }
-clap = { version = "4.4", features = ["derive"] }
- 
-common = { path = "../common" }
 
-[dev-dependencies]
 common = { path = "../common", features = ["test-utils"] }