This information is unused.
Remove "mailbox counters" from `MailboxManager::search` MailboxMetdata POJO.
JMAP-draft and JMAP-RFC8621 will need to rely on a brand new `mailboxManager.getMailboxCounters(ids)` calls as part of `Mailbox/get`.
This is even more important to avoid paying the price of mailbox-counters read repairs upon IMAP LIST.
= Definition of done
Using glowroot on DEV (or locally on a distributed-james server), access your mailbox via IMAP and Thunderbird.
Go in the IMAP LIST transaction, there should be no "mailbox counters" calls.
While looking at the Glowroot board:
We saw that we have some IMAP list slow traces, mostly due to the (very) high count of mailboxes... (104)
A closer look at executed queries shows around a third of the query time is spent retrieving mailbox counters. Which is not part of the IMAP list response.