perf(audio): optimize AudioManager::addAudioEvent

[bobtista]

• Closes Optimize AudioManager::addAudioEvent() #1352

Optimizes AudioManager::addAudioEvent() to avoid wasted allocations and computations for sounds that won't play locally.

Changes:

• Use static string constant to avoid repeated "NoSound" string allocations
• Check shouldPlayLocally() before expensive operations

[Mauller]

You don't need retail compatible CRC here, audo at this point is client side only.

But to test just build the game in VC6 and run a set of replays back.