Rose Edit: Fill in test holes

[wxtim]

Consider adding additional test data types for parts of the code-base which are not covered by the existing demo examples in demo/rose-config-edit/demo_meta.

These appear to include:

Value hints

[env=suggested_fruit]
value-hints=pineapple,cherry,banana,apple,pear,mango,kiwi,grapes,peach,fig,
           =orange,strawberry,blackberry,blackcurrent,raspberry,melon,plum

BoolValueWidget

It's not clear that this is actually working!

[env=cake]
type=boolean
widget[rose-config-edit]=metomi.rose.config_editor.valuewidget.boolradio.BoolValueWidget
# Rose 2019 for comparison
# widget[rose-config-edit]=rose.config_editor.valuewidget.boolradio.BoolValueWidget

ChoicesValueWidget

[env=duck]
type=character
widget[rose-config-edit]=rose.config_editor.valuewidget.choice.ChoicesValueWidget
                        =--editable
                        =mallard
                        =widgeon
                        =teal

FormatsChooserWidget

[env=biscuit]
title=Biscuit
help=Wooble
description=Type of biscuit to have with ones tea
values="Rich Tea","Nice","Malted Milk"
value-titles=poor,ok,good
widget[rose-config-edit]=rose.config_editor.valuewidget.format.FormatsChooserValueWidget