Support multiple function arguments in `couler.map()`

[terrytangyuan]

We currently only support one argument in couler.map(), which is a list of values that can be called by the specified function.

https://github.com/couler-proj/couler/blob/fedbcc42383eb3335d3fadddf818defcf74d70a4/couler/core/syntax/loop.py#L23-L32

[reprabhala]

@terrytangyuan can I pick this up as well?

[terrytangyuan]

Sure