Lower precision for most search space variables

[vertti]

Summary

Lower the precision of most search space variables for hyperopt.

Quick changelog

Makes hyperopt step size 5.0 instead of 1.0 for variables like RSI, ADX, MFI etc.
Makes stoploss search step 2% at time.

These changes should:

1. Lower the size of search space to 1/10000 of what it was
2. Reduce the unnecessary overfitting to a specific dataset

[shusso]

looks good 👍