Fix critical bugs in get_unoptimized_hlsmodel() in profiling.py
Created by: maksgraczyk
This PR fixes the following issues:
- When
hls4ml.model.profiling.numerical()
is called with a model, all 'Optimizers' and 'SkipOptimizers' entries in the model internal config are cleared or deleted instead of being left intact. - When
hls4ml.model.profiling.numerical()
is called with a model that has 'SkipOptimizers' in its dictionary config, the function fails to obtain the unoptimised version of the model because of a crash.