Implement FURB136 (#8664)
## Summary
Implements
[FURB136](https://github.com/dosisod/refurb/blob/master/docs/checks.md#furb136-use-min-max)
that checks for `if` expressions that can be replaced with `min()` or
`max()` calls. See issue #1348 for more information.
This implementation diverges from Refurb's original implementation by
retaining the order of equal values. For example, Refurb suggest that
the following expressions:
```python
highest_score1 = score1 if score1 > score2 else score2
highest_score2 = score1 if score1 >= score2 else score2
```
should be to rewritten as:
```python
highest_score1 = max(score1, score2)
highest_score2 = max(score1, score2)
```
whereas this implementation provides more correct alternatives:
```python
highest_score1 = max(score2, score1)
highest_score2 = max(score1, score2)
```
## Test Plan
Unit test checks all eight possibilities.
