testing/ikona: modernize
- Add missing bash-completion subpackage
- Add missing zsh-completion subpackage
- Add missing fish-completion subpackage
- Install to 'lib' not 'lib64'
We are currently working on getting Alpine Linux 3.21 out. This means that merge requests that are not aimed to help with that (only affecting testing, new aports) have a lower priority at the moment. Please be patient, they will be eventually picked up.