Pitch sampling interval conflicts when importing svp with overlapped groups

[sdercolin]

Cause

In svp, if:

• notes with vibrato are written in a group
• pitch points directly are written in the track

The current algorithm cannot align the vibrato points and pitch points to the same sampling points, so the merging process fails, causing a seesaw-like result.

Solution

Two types of solutions maybe effective to solve this:

1. Merge all the groups to have all notes and all pitch points together before starting the process
2. Use absolute interval interpolation (only interpolate points when the absolute time tick value % sampling interval == 0
   But both of them will cause an overall change in the svp pitch import algorithm and result, so we need more time and testing to fix it without causing other issues.