Merge pull request #9772 from rafaeltonholo/fix/9567/duplicated-imap-prefix

fix: correctly handles the server ID when an IMAP prefix is present, ensuring the prefix is not duplicated
# Conflicts:
#	legacy/storage/src/main/java/com/fsck/k9/storage/StoreSchemaDefinition.java
#	legacy/storage/src/main/java/com/fsck/k9/storage/migrations/Migrations.kt