setup osx signing

[maxandersen]

see https://localazy.com/blog/how-to-automatically-sign-macos-apps-using-github-actions for details

[fahad-israr]

@maxandersen this issue is a major roadbloack. If we solve this, we can go ahead with a complete release.

[fahad-israr]

Due to this issue we haven't been able to deliver starfix to mac users.

[maxandersen]

Yes. I never got the key to work :/

[fahad-israr]

Yes. I never got the key to work :/

Was at start of my career with my current orgs work being pretty intensive & i spend weekends for detox. Things are becoming better now, I am hoping to plan out something to dedicate part of weekend towards open source regularly.