feat: Implement Dehydrated Devices MSC3814

Co-authored-by: Jade Ellis <jade@ellis.link>
Signed-off-by: Jason Volk <jason@zemos.net>

src/database/maps.rs

@@ -362,6 +362,10 @@ pub(super) static MAPS: &[Descriptor] = &[
 		name: "userid_blurhash",
 		..descriptor::RANDOM_SMALL
 	},
+	Descriptor {
+		name: "userid_dehydrateddevice",
+		..descriptor::RANDOM_SMALL
+	},
 	Descriptor {
 		name: "userid_devicelistversion",
 		..descriptor::RANDOM_SMALL