[BOLT] introducing profi params

We want to use profile inference (**profi**) in BOLT for stale profile matching.
To this end, I am making a few changes modifying the interface of the algorithm.
This is the first change for existing usages of profi (e.g., CSSPGO):
- introducing an object holding the algorithmic parameters;
- some renaming of existing options;
- dropped unused option, SampleProfileInferEntryCount, as we don't plan to change its default value;
- no changes in the output / tests.

Reviewed By: hoy

Differential Revision: https://reviews.llvm.org/D134756