Improve escort trip modelling

[Hussein-Mahfouz]

Escort trips have different purposes, whereas currently we do this:

acbm/scripts/2_match_households_and_individuals.py

Lines 1066 to 1071 in 9f8790c

	17: "escort", #'Escort home',
	18: "escort", #'Escort work',
	19: "escort", #'Escort in course of work',
	20: "escort", #'Escort education',
	21: "escort", #'Escort shopping/personal business',
	22: "escort", #'Other escort',

We can improve modelling of escort trips by specifying escort_education, escort_work etc. Then downstream when assigning facility locations we can use facilities that match the escort type.

We may need to add logic to ensure that a discretionary activity is assigned to a zone that has that activity type here

For reference from the NTS