#415 - offer to move transactions to category on category delete

...adlocker8/budgetmaster/categories/CategoryController.java

.../deadlocker8/budgetmaster/categories/CategoryService.java

...dlocker8/budgetmaster/categories/DestinationCategory.java

...ker8/budgetmaster/transactions/TransactionController.java

src/main/resources/languages/_de.properties

src/main/resources/languages/_en.properties

src/main/resources/static/js/categories.js

src/main/resources/static/js/categorySelect.js

src/main/resources/static/js/transactions.js

src/main/resources/templates/categories/categories.ftl

src/main/resources/templates/transactions/newTransaction.ftl

...resources/templates/transactions/newTransactionMacros.ftl