[ScriptAPI] ScoreboardObjective::removeParticipant & ScoreboardObjective::getScore fails when using not defined identity

When using methods such as removeParticipants or getScore they fails and throw an error instead of returning undefined or false

Steps to reproduce:

• Create Scoreboard objectvive if not exist
• try to remove random string from objective
• try to remove random entity from objective

Observed Results:

Throw error: Failed to resolve identity for '...'

Expected Results:

methods should return false or undefined as is intended

Pack to reproduce: ScoreboardsObjectiveMethods fails.js.mcpack