Specify that application services receive events in the CSAPI format
Specify that application services receive events in the CSAPI format

Fixes https://github.com/matrix-org/matrix-doc/issues/1269

This is also supposed to fix the 'age' problem, however that is a larger problem with the event schemas that is reserved for a future PR/commit.
Reference: https://github.com/matrix-org/matrix-doc/issues/1294
Reference: https://github.com/matrix-org/matrix-doc/issues/1524
matrix-org/matrix-doc,matrix-org/matrix-doc,matrix-org/matrix-doc,matrix-org/matrix-doc