refactor: Rename all remaining conduwuit references to Continuwuity

Also adds an alias for the old binary name to the dockerfile

Supersedes !1485
Closes #1536
Closes #2277

docs/deploying/kubernetes.mdx

@@ -39,7 +39,7 @@ spec:
         - name: continuwuity
           # use a sha hash <3
           image: forgejo.ellis.link/continuwuation/continuwuity:latest
-          command: ["/sbin/conduwuit"]
+          command: ["/sbin/continuwuity"]
           imagePullPolicy: IfNotPresent
           ports:
             - name: http