Make type cast fully support the current subset

[heshanpadmasiri]

#132 will be necessary to implement this. We need to support fallowing

1. Numeric conversion should support types that are subsets for int, float, decimal
2. Casting list
3. Casting map

For both 2 and 3 (may be for 1 as well) we shoud be able to implement a generic version that uses the type of the value and just check if it a subtype of the target type