Use a dictionary for StreamField errors
Use a dictionary for StreamField errors

Instead of filling an array with `None` to indicate no errors, a
dictionary is only set when there is an actual error. This will allow
future functionality for errors to be added to the StreamField itself,
rather than a block, similar to adding errors to a form rather than a
specific field.

davecranwell/wagtail,iansprice/wagtail,kaedroho/wagtail,takeflight/wagtail,kaedroho/wagtail,FlipperPA/wagtail,FlipperPA/wagtail,kurtrwall/wagtail,nilnvoid/wagtail,jnns/wagtail,Toshakins/wagtail,chrxr/wagtail,mixxorz/wagtail,timorieber/wagtail,FlipperPA/wagtail,nealtodd/wagtail,quru/wagtail,thenewguy/wagtail,mixxorz/wagtail,mixxorz/wagtail,zerolab/wagtail,jnns/wagtail,kaedroho/wagtail,gogobook/wagtail,Toshakins/wagtail,JoshBarr/wagtail,kurtw/wagtail,quru/wagtail,inonit/wagtail,gogobook/wagtail,gasman/wagtail,timorieber/wagtail,mixxorz/wagtail,quru/wagtail,kurtw/wagtail,wagtail/wagtail,mixxorz/wagtail,inonit/wagtail,rsalmaso/wagtail,rsalmaso/wagtail,takeflight/wagtail,mikedingjan/wagtail,wagtail/wagtail,timorieber/wagtail,thenewguy/wagtail,nutztherookie/wagtail,mikedingjan/wagtail,torchbox/wagtail,JoshBarr/wagtail,Toshakins/wagtail,wagtail/wagtail,rsalmaso/wagtail,chrxr/wagtail,jnns/wagtail,nutztherookie/wagtail,torchbox/wagtail,davecranwell/wagtail,nilnvoid/wagtail,nimasmi/wagtail,zerolab/wagtail,hamsterbacke23/wagtail,torchbox/wagtail,quru/wagtail,gasman/wagtail,mikedingjan/wagtail,kurtrwall/wagtail,chrxr/wagtail,kurtrwall/wagtail,wagtail/wagtail,jnns/wagtail,nealtodd/wagtail,hamsterbacke23/wagtail,nealtodd/wagtail,thenewguy/wagtail,JoshBarr/wagtail,nimasmi/wagtail,mikedingjan/wagtail,nimasmi/wagtail,gogobook/wagtail,wagtail/wagtail,nimasmi/wagtail,gasman/wagtail,iansprice/wagtail,zerolab/wagtail,iansprice/wagtail,gasman/wagtail,kurtrwall/wagtail,inonit/wagtail,kaedroho/wagtail,Toshakins/wagtail,takeflight/wagtail,nutztherookie/wagtail,gasman/wagtail,torchbox/wagtail,nilnvoid/wagtail,inonit/wagtail,hamsterbacke23/wagtail,iansprice/wagtail,JoshBarr/wagtail,nealtodd/wagtail,hamsterbacke23/wagtail,kurtw/wagtail,timorieber/wagtail,nutztherookie/wagtail,zerolab/wagtail,kurtw/wagtail,takeflight/wagtail,rsalmaso/wagtail,FlipperPA/wagtail,chrxr/wagtail,zerolab/wagtail,thenewguy/wagtail,thenewguy/wagtail,rsalmaso/wagtail,davecranwell/wagtail,davecranwell/wagtail,kaedroho/wagtail,nilnvoid/wagtail,gogobook/wagtail