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.

crates/store/src/backend/ephemeral/main.rs

@@ -0,0 +1,21 @@
+/*
+ * SPDX-FileCopyrightText: 2020 Stalwart Labs LLC <[email protected]>
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-SEL
+ */
+
+use super::{EphemeralState, EphemeralStore};
+use crate::Store;
+use ahash::AHashMap;
+use parking_lot::RwLock;
+use std::sync::Arc;
+
+impl EphemeralStore {
+    pub fn open() -> Store {
+        Store::Ephemeral(Arc::new(EphemeralStore {
+            state: RwLock::new(EphemeralState {
+                subspaces: AHashMap::new(),
+            }),
+        }))
+    }
+}