Tracker script improvements (#1048)

lib/plausible_web/endpoint.ex

lib/plausible_web/plugs/tracker.ex

priv/tracker/js/analytics.js

priv/tracker/js/p.js

priv/tracker/js/plausible.exclusions.hash.js

priv/tracker/js/plausible.exclusions.hash.outbound-links.js

priv/tracker/js/plausible.exclusions.js

priv/tracker/js/plausible.exclusions.outbound-links.js

priv/tracker/js/plausible.hash.exclusions.js

priv/tracker/js/plausible.hash.exclusions.outbound-links.js

priv/tracker/js/plausible.hash.js

priv/tracker/js/plausible.hash.outbound-links.js

priv/tracker/js/plausible.js

priv/tracker/js/plausible.outbound-links.js

tracker/package-lock.json

tracker/src/plausible.js