Do not apply the autocompleted text into the text field on keyboard navigation

[mvysny]

Steps to reproduce:

1. Open https://incubator.app.fi/autocomplete-demo/autocomplete
2. Type in "ky"
3. Press the arrow down to select "Kylie".

The current input shows "ky" while the autocomplete text field shows "Kylie". This is confusing, since the user thinks that the "Kylie" value is applied, however the autocomplete component fired no such event and reports its value server-side as "ky".

I suggest to change this behavior to set the text field to "Kylie" only after ENTER has been pressed while the "Kylie" option is highlighted in the dropdown; that should then immediately fire the onValueChange event as well.