Add Chat API support

[belyaev-dev]

We need to update requests module so we can add Chats API support. Currently it's not possible even using raw amoCRM API requests.

Docs: amoCRM and Kommo

Required methods:

• Connect channel
• Disconnect channel
• Create chat
• Link chat to contact (update contact entity)
• Send message (incoming/outgoing)
• Get chat history
• Update delivery status
• Typing infomation
• Send reaction
• Withdraw reaction

Required webhooks:

• Outgoing message webhook

Required integration tokens, received from amoCRM when registering new Chats API integration:

1. AMOJO_UUID
2. AMOJO_BOT_UUID
3. AMOJO_SECRET

Required account data:

1. ACCOUNT_AMOJO_ID (received by /api/v4/account?with=amojo_id req)
2. SCOPE_ID (consists of ${AMOJO_UUID}_${ACCOUNT_AMOJO_ID})

We also need to constuct complex headers using request body to work with chats API, example:

import { createHash } from "https://deno.land/std@0.91.0/hash/mod.ts";
import { hmac } from "https://deno.land/x/hmac@v2.0.1/mod.ts";

private getHeaders(body: object): Headers {
    const contentType = "application/json";
    const date = new Date().toUTCString().replace(
      /(\w+), (\d+) (\w+) (\d+) (\d+):(\d+):(\d+) GMT/,
      "$1, $2 $3 $4 $5:$6:$7 +0000",
    );
    const requestBody = JSON.stringify(body);
    const checkSum = createHash("md5").update(requestBody).toString("hex");

    const signature = hmac("sha1", AMOJO_SECRET, requestBody, "utf8", "hex").toString();

    const headers = new Headers();
    headers.append("Date", date);
    headers.append("Content-Type", contentType);
    headers.append("Content-MD5", checkSum);
    headers.append("X-Signature", signature);

    return headers;
  }

Any help is appreciated