Import upstream v0.16.22, stripped

Upstream commit: 474dd0229cb20cf513036619781ed97bd8073c3f
Enterprise-only files removed or emptied: 63
Enterprise-only snippets removed: 117 in 50 files
Dangling module declarations removed: 5
Cargo edits turning enterprise off: 14
Verification: clean
Enterprise feature gates left for rebuilt features: 19 in 18 files

Produced by tools/fork/strip.py. The full report is in docs/fork/strip-reports/ on main.

tests/resources/imap-test/pipeline

@@ -0,0 +1,23 @@
+state: auth
+
+tag1 create ${mailbox}
+tag2 create ${mailbox}2
+tag3 create ${mailbox}3
+tag4 create ${mailbox}4
+tag1 ok
+tag2 ok
+tag3 ok
+tag4 ok
+
+tag1 status ${mailbox} (messages)
+tag2 status ${mailbox}2 (messages)
+tag3 status ${mailbox}3 (messages)
+tag4 status ${mailbox}4 (messages)
+* status ${mailbox} (messages 0)
+* status ${mailbox}2 (messages 0)
+* status ${mailbox}3 (messages 0)
+* status ${mailbox}4 (messages 0)
+tag1 ok
+tag2 ok
+tag3 ok
+tag4 ok