Complete refactoring of the templating in entity-factory

addon/components/multiple-entity-selector.js

addon/templates/components/multiple-entity-selector.hbs

app/components/multiple-entity-selector.js

app/router.js

...y-factory/files/__root__/__mirage__/factories/__name__.js

...tity-factory/files/__root__/__mirage__/models/__name__.js

...ory/files/__root__/controllers/entity-factory/__name__.js

blueprints/entity-factory/files/__root__/models/__name__.js

...tory/files/__root__/templates/entity-factory/__name__.hbs

...nts/entity-factory/files/__root__/validations/__name__.js

blueprints/entity-factory/index.js

mirage/config.js

mirage/scenarios/default.js

package.json

tests/dummy/mirage/scenarios/default.js