Relating to teachers; extending eligibility for extended leaves of absence to teach at charter schools to employees of cooperatives or other teacher professional associations providing instructional or other services to the school; expanding the definition of teacher for teachers retirement association (TRA) or fund association coverage clarification purposes to persons rendering services as teachers, supervisors, principals, superintendents, librarians, nurses, counselors, social workers, therapists and psychologists in public schools including charter schools as employees of teacher professional associations (ra)