IOS os_version should give specific version number

[blairjo]

Is your feature request related to a problem? Please describe.
On an IPhone or IPad the os_version is simply "iOS" or sometimes "unknown"

Describe the solution you'd like
It should give the ios version, 16.0.0 etc..

Describe alternatives you've considered
I looked at alternative libraries that give the version number correctly, but would rather stick with this one.