feat: add configurable options for Phase2 MPC setup

[crStiv]

Description

Added configuration options to the Phase2 MPC setup, including support for custom randomness sources when generating contributions. This makes the setup process more flexible and easier to test in different environments.

Fixes #1428

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How has this been tested?

• Added tests for custom random source
• Added tests for default options
• All existing tests pass

How has this been benchmarked?

• No performance impact on existing functionality

Checklist:

• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I did not modify files generated from templates
• golangci-lint does not output errors locally
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules