#267 - added input for tags (including autocomplete)

...eadlocker8/budgetmaster/controller/PaymentController.java

.../deadlocker8/budgetmaster/repositories/TagRepository.java

.../de/deadlocker8/budgetmaster/services/HelpersService.java

src/main/resources/languages/_de.properties

src/main/resources/languages/_en.properties

src/main/resources/static/css/style.css

src/main/resources/static/js/payments.js

src/main/resources/templates/payments/newPayment.ftl