What number of cases of attempted murder by (a) learners on learners, (b) learners on educators and support staff, (c) educators and support staff on learners, (d) educators on educators, (e) support staff on support staff, (f) support staff on educators and (g) educators on support staff have been reported in each district in each province (i) in each of the last three academic years and (ii) since 1 January 2018?