PHRAS-2995 auth-service as identification provider - refacto authentication

[jygaulier]

WIP do not merge

Changelog

Adds

• PHRAS-2995: - new "phraseanet" provider, based on github provider

sample conf :

authentication:
    providers:
        phraseanet-test:
            enabled: true
            display: true
            title: Phraseanet
            type: phraseanet-oauth
            options:
                client-id: 'xxxxx'
                client-secret: 'yyyy'
                base-url: 'https://www.phraseanet-oauth.fr'
                provider-type: 'oauth'
                provider-name: 'phraseanet'
                icon-uri: 'http://icons.iconarchive.com/icons/martz90/circle-addon1/48/go-locker-icon.png'