JAMES-4028 MailImpl: More compact version of Mail.getName

On a production system we encountered a JMAP query for which the clause count
of OpenSearch (- 1024) was exceeded. This commit makes sure that it is not
linked to the overall right filtering strategy pushing the mailboxes to search
in onto the search query.
diff --git a/server/container/core/src/main/java/org/apache/james/server/core/MailImpl.java b/server/container/core/src/main/java/org/apache/james/server/core/MailImpl.java
index d1c5aa7..6f2a24c 100644
--- a/server/container/core/src/main/java/org/apache/james/server/core/MailImpl.java
+++ b/server/container/core/src/main/java/org/apache/james/server/core/MailImpl.java
@@ -31,7 +31,6 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.UUID;
 import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -44,7 +43,6 @@
 import jakarta.mail.internet.ParseException;
 
 import org.apache.commons.lang3.RandomStringUtils;
-import org.apache.commons.lang3.StringUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import org.apache.james.core.MailAddress;
 import org.apache.james.core.MaybeSender;