Prevent OptimizationSolver from reinstantiating the associated process

[AlessandroPierro]

Objective of issue: prevent the OptimizationSolver from re-instantiating its process when called multiple times.

Lava version:

• [x] 0.3.0

I'm submitting a ...

• [ ] bug report
• [ ] feature request
• [ ] documentation request

Current behavior:

• The associated process is instantiated from scratch for each call to the solve method

Expected behavior:

• Prevent the re-instantiation of the process, but keeping the ability to call the solve method multiple time (this is essential for the SolverTuner to operate correctly)