Use randomly generated conference names for Jitsi

Fixes https://github.com/vector-im/element-web/issues/15205
Replaces https://github.com/matrix-org/matrix-react-sdk/pull/5322

This change uses a random ID for the Jitsi conference name to avoid any badly-named Jitsi calls, and overrides the "subject" (title) of the call so end users aren't typically exposed to the random ID.

package.json

@@ -86,7 +86,6 @@
     "pako": "^2.0.3",
     "parse5": "^6.0.1",
     "png-chunks-extract": "^1.0.0",
-    "project-name-generator": "^2.1.9",
     "prop-types": "^15.7.2",
     "qrcode": "^1.4.4",
     "qs": "^6.9.6",