chore: use Shouldly

tests: add game friends tests

chore: add Game test files with comments saying what tests to implement

tests(game): add basic test for mates

chore: add game tests to solution

tests(game): add support for game integration tests

chore: filter out NosSmooth.Game.Tests from dotnet test

CI does not contain needed NostaleData files.

tests: remove unnecessary deep checks, replace them with ShouldBeEquivalentTo from Shouldly

Merge pull request #55 from Rutherther/feat/contracts

Add contract system

feat(game): split nostale apis into safe, unsafe, add contracts usage

feat(game): make item dropped event contain ground item

feat(core): add default states and no errors enum

feat(core): add contract builder

feat(game): add event constraint for IEveryGameResponder Respond

feat(game): add timeouts to contracts

feat(core): add contract builder outline

feat(game): add every game event responder

feat(core): add basics of a contract system

fix(game): make current partner and pet null if pinit does not contain them

fix(packets): make pinit sub packet unknowns nullable