Better reflect custom entrance sounds to the user in voice calls

When using a custom entrance sound, the sound that plays on your own end when joining a VC is still the default "join vc" sound. However, because custom entrance sounds can be differing length, and because the user can only be heard by others after their entrance sound has completed, it's hard to know whether ones custom entrance sound succeeded and whether you're ready to speak

When using a custom entrance sound, replace the join vc sound that plays when you yourself join a vc with your entrance sound, so that you yourself can hear it too

iirc discord does this but whether it does is besides the point anyway