internal/web3ext, les: update clique JS and make it work with the light client (#20318)

Also fix the input formatter on clique_getSnapshot and clique_getSigners
so that integers as well as hex number strings are accepted.

les/client.go

@@ -176,7 +176,9 @@ func (s *LightDummyAPI) Mining() bool {
 // APIs returns the collection of RPC services the ethereum package offers.
 // NOTE, some of these services probably need to be moved to somewhere else.
 func (s *LightEthereum) APIs() []rpc.API {
-	return append(ethapi.GetAPIs(s.ApiBackend), []rpc.API{
+	apis := ethapi.GetAPIs(s.ApiBackend)
+	apis = append(apis, s.engine.APIs(s.BlockChain().HeaderChain())...)
+	return append(apis, []rpc.API{
 		{
 			Namespace: "eth",
 			Version:   "1.0",