Add boolean publisherActionAllowed property to cancel publisher action with config settings

[TMSchipper]

This feature will resolve:
#194
#142

You can test this by adding this to your config:

export default () => ({
    'seo': {
        enabled: true,
    },
    'publisher': {
        enabled: true,
        config: {
            contentTypes: ['api::article.article'],
            hooks: {
                beforePublish: async ({ strapi, uid, entity }) => {
                    return false;
                },
                afterPublish: async ({ strapi, uid, entity }) => {
                    // Post-publish side effects
                },
                beforeUnpublish: async ({ strapi, uid, entity }) => {
                    // Return false to prevent unpublish
                    return false;
                },
                afterUnpublish: async ({ strapi, uid, entity }) => {
                    // Post-unpublish side effects
                },
            },
        }
    },
});

[boazpoolman]

LGTM!