Entry Editor: general changes

[MartinKarim]

Description of Issue	Possible Solution	Warnings
Text fields are empty per default; there is no guide what to write in a field and in what form (e.g. text, numbers)	text suggestions in grey for every text field	font color needs to be very different from normal text; do not use suggestions if the form of input can vary;
flat buttons at the end of text fields are too inconspicuous; button icons are not always recognized	make buttons bigger and elevated; use text buttons, sometimes in combination with icons	-
too many tabs in the entry editor; some information repeats in other tabs; information structure does not match the users expectation;	remove tabs from the entry editor; divide fields on new tabs with more fitting structure;	-
		changes to the specific tabs can be found in #4687 #4688 #4689 #4690 #4691

[LinusDietz]

I like the change with the more explicit button. I would prefer if it would shorten the field instead of being in a separate column. (here the prototype is maybe a bit misleading)