add arbitrary property to seo metadata

add  to sonata page service, fixes for CS

add frontend test

fix CS

add extractor

ChangelLog entry

fix typ

add form for admin extension

fix admin tests

extract test, cs fixes, licences

cs fixes to clear the review

more fixes

more fixes

init multi type functionality of the arbitrary properties

train SeoPresentation to set arbitrary properties by its type

refactor class name

redo constructor injection add test cases

default for type, CS fixing

rename method

add admin support for type

rename form type, add an form service, error stays

reorder setting values to PageService

use form extension, cs fixes

fixes on form type, but error stays

allowedType as static

kill default, use static property, all fine

type should not change

now i do really delete the right method

fixes

CS fixes, new dependency, type check in constructor

test for type check

Typehint to interface instead of implementation