ASR: [BUG] Error while using dot to access module variable

```py
% cat a.py
import math

def f():
    print(math.pi, math.e)

f()
```

LPython Output:
```
% lpython a.py 
semantic error: Only Variable type is supported for now in Attribute
 --> a.py:4:11
  |
4 |     print(math.pi, math.e)
  |           ^^^^^^^ 
```

CPython:
```
% python a.py 
3.141592653589793 2.718281828459045
```
