Function get_context_slice_op 

pub fn get_context_slice_op(
    workspace: &Workspace,
    db_path: &Path,
    conn: &Connection,
    symbol_name: &str,
    file_path: Option<&str>,
    include_external: bool,
) -> Result<ContextSlice, OpError>

Retrieve a complete context slice for a symbol, guaranteeing fresh offsets.