Add support for printing shoppinglist with thermal printer (#1273)

* Added escpos-php library

* Added button to shoppinglist print menu

* Added to translation

* Added basic printing logic and API call

* Working implementation for printing with the API

* Added openapi json

* Correctly parsing boolean parameter

* Working button in UI

* Change to grocy formatting

* Add Date

* Only show thermal print button when Feature Flag is set

* Fixed API call and added error message parsing

* Undo translation

* Add flag to print quantities as well

* Added printing notes

* Added quantity conversion

* Increse feed

* Fixed that checkbox was undefined, as dialog was already closed

* Added padding

* Formatting

* Added note about user permission

* Fixed error when using notes instead of products

* Review

- Default FEATURE_FLAG_THERMAL_PRINTER to disabled
- Added missing localization strings (and slightly adjusted one)

* Fixed merge conflicts

Co-authored-by: Bernd Bestel <bernd@berrnd.de>

localization/strings.pot

@@ -2129,3 +2129,16 @@ msgstr ""
 
 msgid "Open stock entry print label in new window"
 msgstr ""
+
+msgid "Thermal printer"
+msgstr ""
+
+msgid "Printing"
+msgstr ""
+
+msgid "Connecting to printer..."
+msgstr ""
+
+msgid "Unable to print"
+msgstr ""
+