Feature request: allow to query multiple notes at once (to reduce IPC overhead)

[ofsjoerdk]

Would it be possible to add an alternative version of NoteToFrequency that takes in a range of notes?
Something like

void MTS_NotesToFrequencies(MTSClient *client, char* midinotes, char* midichannels, double* output_freqs, int count);

I think this may be useful to reduce IPC overhead. For example, a plugin can then query the entire range of notes that it expects to use within a single synth voice, using 1 IPC call, instead of potentially up to 128. Of course there should be something similar for note-retuning-ratio, note-returning-semis and a couple other ones.