[Feature Request] Where op for bool input

[wenlonn]

Describe the feature request

support where op with bool inputs

Describe scenario use case

For where op， there is a situation that the X/Y/output is bool type. We try to infer model with this where op, and got an error, which claims that where(9) NOT_IMPLEMNTED. We revise the code and add the declare of bool type where, test the wheel with python. Please support where op with bool inputs in version 1.15.1 +

[wenlonn]

Until now, we find two method to solve this issue, however it costs a lot.

First one, as where op only support float/int type for now, we propose to insert cast_op before the input of where and after the output of where. By the way the op index of inserted cast_op may need to be arranged.
Second one, add bool type where op implement in source code, then compile and install wheel in python. However, we need to maintain the wheel package in our program.

[xadupre]

Since you did the modification to support bool, could you submit a PR?