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/search-context-update

@@ -0,0 +1,35 @@
+capabilities: CONTEXT=SEARCH
+state: created
+
+ok append
+ok append
+ok append
+ok append
+ok append
+
+ok select $mailbox
+
+ok search return (update) body body seen
+* esearch (tag $searchtag)
+
+ok store 1,2,4 +flags \seen
+* esearch (tag $searchtag) addto ($pos 1:2,4)
+
+ok store 1,2 -flags \seen
+* esearch (tag $searchtag) removefrom ($pos2 1:2)
+
+ok store 3:5 +flags \deleted
+ok expunge
+* esearch (tag $searchtag) removefrom ($pos3 $4)
+* $3 expunge
+* $4 expunge
+* $5 expunge
+
+ok append $mailbox (\seen)
+* 3 exists
+* esearch (tag $searchtag) addto ($pos4 3)
+
+ok cancelupdate "$searchtag"
+
+ok store 1 +flags \seen
+! esearch (tag $searchtag) addto ($pos5 1)