Update v3.5.0

Open Ticket v3.5.0 is the statistics update. There are many improvements & one new command (/stats)!

added:

• stats command (global, ticket & user statistics)
• HTML transcripts can now have a custom favicon
• support for the CUSTOM bot status type
• ticket admins can now also use admin commands in their tickets

fixed:

• axios dependabot alert (updated to 1.6.2)
• some emojis didn't display correctly in the HTML transcripts
• changed HTML transcript & livestatus API endpoints
• /reopen slash command could crash due to typo
• updated README.md, CONTRIBUTING.md & SECURITY.md

removed:

• /