Remove pre and post programme stress check-in

[fagiothree]

For Mexico we are going to drop the Stress Reduction question all together. Need to remove pre and post stress questions

[fagiothree]

For pre check-in edited the pre_programme_checkin as follows: https://docs.google.com/spreadsheets/d/1yUzKndclwMurTwBgDTzA5ha7xLjj214oZy10KYtjW4U/edit#gid=384878718

[fagiothree]

For post programme, moved it to time_programme_data https://docs.google.com/spreadsheets/d/1q6E2c4Bg_UvqTmhxAsTIQngwAtj0aFoqu8wsPHnqmaU/edit#gid=2098299731 instead of being part of programme completion congrats. To disable it, pass "empty" flow as argument https://docs.google.com/spreadsheets/d/1yUzKndclwMurTwBgDTzA5ha7xLjj214oZy10KYtjW4U/edit#gid=0