test(compatibility-suite): Build interactions

[tienvx]

• Add InteractionBuilder (+ related services)
• About the code in Parser and FixtureLoader services, I copied most of the logic from these code:
  • https://github.com/pact-foundation/pact-reference/blob/master/compatibility-suite/tests/shared_steps/mod.rs
  • https://github.com/pact-foundation/pact-reference/blob/master/rust/pact_models/src/headers.rs
  • https://github.com/pact-foundation/pact-reference/blob/master/rust/pact_models/src/query_strings.rs

I deleted code that's not related. Will add back in future PR.

Hope the PR is not too big.

[Lewiscowles1986]

Believe it or not, so long as the compatibility suite code stays outside of the rest of the repo; we might be able to work on some larger Patches