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/atoms

@@ -0,0 +1,13 @@
+state: auth
+
+# Don't confuse with ~{literal8}
+ok list "" ~foo
+no select ~foo
+
+# atom-specials   = "(" / ")" / "{" / SP / CTL / list-wildcards /
+#                   quoted-specials / resp-specials
+# quoted-specials = DQUOTE / "\"
+# resp-specials   = "]"
+# list-wildcards  = "%" / "*"
+no select !#$$&'+,-.0123456789:;<=>?@^_`|[}
+ok list "" !#$$&'+,-.0123456789:;<=>?@^_`|[}%*