Merge branch 'test-refactoring' into 'main'

mailbox-core/build.gradle

...in/java/org/briarproject/mailbox/core/contacts/Contact.kt

...rc/main/java/org/briarproject/mailbox/core/db/Database.kt

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

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

.../org/briarproject/mailbox/core/server/WebServerManager.kt

...a/org/briarproject/mailbox/core/system/RandomIdManager.kt

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

...java/org/briarproject/mailbox/core/db/JdbcDatabaseTest.kt

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

...arproject/mailbox/core/server/WebServerIntegrationTest.kt