Database entries can be added/edited by just a bone prefill

[phorward]

Will be solved in the admin

• Filter out error of bones where client data was missing
• Use bounce

Originally posted by @sveneberth in viur-framework/viur-core#1220 (comment)

[phorward]

From #1220:

Working test scenario:

skeletons/test.py

from viur.core import skeleton
from viur.core.bones import *


class TestSkel(skeleton.Skeleton):
    name = StringBone(
        descr="Name",
        required=True,
        defaultValue="Test",
    )

modules/test.py

from viur.core.prototypes import List


class Test(List):
    pass

Reproduction

Call the vi-admin in an empty tab using http://localhost:8080/vi/s/main.html#/db/test/add?name=Hello, an entry with name "Hello" is immediately created.