Convert more DB access to new TransactionManager

...ox-cli/src/main/java/org/briarproject/mailbox/cli/Main.kt

...org/briarproject/mailbox/core/contacts/ContactsManager.kt

...ain/java/org/briarproject/mailbox/core/db/JdbcDatabase.kt

...va/org/briarproject/mailbox/core/db/TransactionManager.kt

...n/java/org/briarproject/mailbox/core/files/FileManager.kt

.../java/org/briarproject/mailbox/core/server/AuthManager.kt

...briarproject/mailbox/core/settings/SettingsManagerImpl.kt

...java/org/briarproject/mailbox/core/setup/QrCodeEncoder.kt

.../src/test/java/org/briarproject/mailbox/core/TestUtils.kt

...a/org/briarproject/mailbox/core/server/AuthManagerTest.kt

...va/org/briarproject/mailbox/core/setup/WipeManagerTest.kt