The word "all" is an exaggeration to emphasize the great number of people who came. AT: "many who were sick or possessed by demons" (See: [[rc://en/ta/man/translate/figs-hyperbole]])
The word "city" is a metonym for the people who lived in the city. Here the word "whole" is probably a generalization to emphasize that most people from the city gathered. AT: "Many people from that city gathered outside the door" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-hyperbole]])