bots: SimpleX Calculator demo bot (#7583)

* bots: SimpleX Calculator demo bot

* refactor

* use local server in test

* simplify

* icon

* simplify

* expression

* replies

* improve

* log

* update name in bot address

* @simplex-chat/type: 0.12.0

* simplex-chat nodejs: 7.1.0-beta.4.2

* update dependencies

* option to add domain to bot address

---------

Co-authored-by: Evgeny @ SimpleX Chat <259188159+evgeny-simplex@users.noreply.github.com>

packages/simplex-chat-nodejs/examples/squaring-bot-readme.js

@@ -1,12 +1,12 @@
 (async () => {
   const {bot} = await import("../dist/index.js")
-  const [chat, _user, _address] = await bot.run({
+  await bot.run({
     profile: {displayName: "Squaring bot example", fullName: ""},
     dbOpts: {type: "sqlite", filePrefix: "./squaring_bot"},
     options: {
       addressSettings: {welcomeMessage: "Send a number, I will square it."},
     },
-    onMessage: async (ci, content) => {
+    onMessage: async (ci, content, chat) => {
       const n = +content.text
       const reply = typeof n === "number" && !isNaN(n)
                     ? `${n} * ${n} = ${n * n}`