Polytonic Greek in italics

[StefanPeev]

@dwhieb @HunterLockwood @Crissov @jcrippen @waldyrious In Libertinus Serif there are not Polytonic Greek in the italic bold version. I try to solve this problem in Common Serif and here is the part of the process.

Very important source on the subject: Polytonic Greek: a guide for type designers

[StefanPeev]

Common Serif Polytonic Greek Metrics

[StefanPeev]

Polytoni Greek in Bold Italic is completed.