[FIX] barcodes: don't require suffix for scans

Users don't have to configure their scanner. As stated in the docs/planner,
either wait 50ms between 2 scans or use a suffix.

addons/barcodes/doc/index.rst

@@ -95,7 +95,7 @@ The purpose of this component is to listen to keypresses to detect barcodes, the
 on core.bus inside a 'barcode_event'.
 All keypress events are buffered until there is no more keypress during 50ms or a carriage return / tab is
 inputted (because most barcode scanners use this as a suffix).
-If the buffered keys looks like a barcode (match the the regexp /.{3,}[\n\r\t]+), an event is triggered :
+If the buffered keys looks like a barcode (match the the regexp /.{3,}[\n\r\t]*), an event is triggered :
 core.bus.trigger('barcode_scanned', barcode);
 Otherwise, the keypresses are 'resent'. However, for security reasons, a keypress event programmatically
 crafted doesn't trigger native browser behaviors. For this reason, BarcodeEvents doesn't intercept keypresses

addons/barcodes/static/src/js/barcode_events.js

@@ -10,7 +10,7 @@ var BarcodeEvents = core.Class.extend(mixins.PropertiesMixin, {
     buffered_key_events: [],
     // Regexp to match a barcode input and extract its payload
     // Note: to build in init() if prefix/suffix can be configured
-    regexp: /(.{3,})[\n\r\t]+/,
+    regexp: /(.{3,})[\n\r\t]*/,
     // By knowing the terminal character we can interpret buffered keys
     // as a barcode as soon as it's encountered (instead of waiting x ms)
     suffix: /[\n\r\t]+/,