theme: move styles from invenio-app-rdm to invenio-theme and invenio-administration#3126

JakobMiesner wants to merge 2 commits intoinveniosoftware:masterinveniosoftware/invenio-app-rdm:masterfrom

JakobMiesner:feature/move-stylesJakobMiesner/invenio-app-rdm:feature/move-stylesCopy head branch name to clipboard