typedef-whitespace: Extract `getOptionType` helper (#2807)
typedef-whitespace: Extract `getOptionType` helper (#2807)


IllusionMH/tslint,andy-ms/tslint,IllusionMH/tslint,mprobst/tslint,berickson1/tslint,palantir/tslint,palantir/tslint,andy-ms/tslint,palantir/tslint,mprobst/tslint,berickson1/tslint,andy-hanson/tslint,mprobst/tslint,andy-hanson/tslint,JoshuaKGoldberg/tslint,JoshuaKGoldberg/tslint,andy-ms/tslint,JoshuaKGoldberg/tslint,berickson1/tslint,IllusionMH/tslint,andy-hanson/tslint