Nostr dm notifications (#3473)

* Add nostr DM notification provider

* require crypto for node 18 compatibility

* remove whitespace

Co-authored-by: Frank Elsinga <frank@elsinga.de>

* move closer to where it is used

* simplify success or failure logic

* don't clobber the non-alert msg

* Update server/notification-providers/nostr.js

Co-authored-by: Frank Elsinga <frank@elsinga.de>

* polyfills required for node <= 18

* resolve linter warnings

* missing comma

* better websocket polyfill, update deprecated function

* add conditional polyfills for node versions

* lint

* use correct npm for package-lock

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Co-authored-by: Frank Elsinga <frank@elsinga.de>
Co-authored-by: Louis Lam <louislam@users.noreply.github.com>

src/components/NotificationDialog.vue

@@ -126,6 +126,7 @@ export default {
                 "lunasea": "LunaSea",
                 "matrix": "Matrix",
                 "mattermost": "Mattermost",
+                "nostr": "Nostr",
                 "ntfy": "Ntfy",
                 "octopush": "Octopush",
                 "OneBot": "OneBot",