Add LastFm cog and emoji support

**__update: last.fm cog__**
- added a Last.fm cog for music stats and now playing info
- improved trading system with atomic item transfer in the database
- fun lil message block for devs: "don’t forget to set your LASTFM_API_KEY!"
- notable: .fm, .fmtopartists, .fmtoptracks commands now available
- **feature 1**
- last.fm integration: fetch now playing, top artists, and top tracks
(no more dupes or losses)
- **feature 2**
- improved error handling for missing config files and duplicate commands
- __bug fixes__
- fixed missing application_id for slash commands
- fixed missing MAIN_GUILD_IDS attribute in bot
- fixed FileNotFoundError for welcome.json
- fixed duplicate command/alias registration errors

Author: rustybusgaming

bronxbot.py

@@ -178,6 +178,7 @@ async def before_update_guilds(self):
         "cogs.economy.Gambling": "success",
         "cogs.economy.Work": "success",
         "cogs.economy.Bazaar": "success",
+        "cogs.LastFm": "success",
     },
     "colors": {
         "error": "\033[31m",      # Red