Previously I wanted to change the default behavior of begin() as was done in #237 as by default it was doing hidden functionality of catching errors silently and attaching them to the report generated. However this new default behavior of not implicitly doing this without being specified by the user would require a deprecation cycle and give annoying warnings.

When considering the base case of what begin would do, is that it would only have the functionality of profile("trial"), i.e. it was a preset profile block we required the user to do.

# New proposed default behavior of `begin()` would make these two equivalent

with trial.begin():
   # ...
   
with trial.profile("trial"):
   # ...

In the interest of keeping things simple and requiring the user to know and do less, I believe it easier to simply remove the begin() block, making writing eval functions less strict.

As an effect of this, if some optimizer requires knowing how long a trial took, there is no codified way we can know this and so a parameter was added to the integrated optimizers. We can reconsider this if it becomes problematic.