* Feature: Implement /rewrite command for message improvement using ChatGPT

* feature "rewrite-msg command": applies changes due to Zabu's first review;

* feature "rewrite-msg command": applies changes due to Wazei's first review - Part 1;

* feature "rewrite-msg command": applies changes due to Wazei's first review - Part 2;

* feature "rewrite-msg command": applies changes due to Wazei's first review - Part 3;

* feature "rewrite-msg command": removing Optional and other adjustments

* feature "rewrite-msg command" - reply to taz 2nd review;

1. ChatGptService: MAX_TOKENS value updated to 500;
2. RewriteCommand: Adding more precision in Ai Prompt message;

* ChatGptService: MAX_TOKENS value updated to 1000;

* fix: AI message dismiss button

when message that created thread was deleted,
retrieveStartMessage() threw an error UNKNOWN_MESSAGE
leading to non-functional dismiss button.

this adds a handler, specifically for parent message
deleted error by using getIterableHistoryInstead.

* refactor: HelpThreadCreatedListener

* move AI dismiss fallback consumer to a seperate function for clarity
* move variable FIRST_MESSAGE_ONLY to function scope as noOfMessage for
  clarity
* improve error log message for clarity