Fixed #186 - Add possibility to search by amount/amount range

...dlocker8/budgetmaster/logic/search/SearchPreferences.java

...budgetmaster/logic/serverconnection/ServerConnection.java

...dlocker8/budgetmaster/ui/controller/SearchController.java

...r8/budgetmasterserver/logic/database/DatabaseHandler.java

...de/deadlocker8/budgetmasterserver/server/SparkServer.java

...tmasterserver/server/payment/search/PaymentMaxAmount.java

...dgetmasterserver/server/payment/search/PaymentSearch.java