weeTrade - Updated to 1.12.2

FULL CREDITS TO Dubehh
https://www.spigotmc.org/resources/weetrade-trading-plugin-1-8-x.6046/

So as many of you may know weeTrade is no longer updated. I saw they had posted the source code so I decided to update it for my network and one of the people I work with told me I should post it here so here it is. So far it only supports 1.12.2 I will try to work on 1.13.2 support but no promises as I am a very bad developer and still learning.

Known issues:
"Prefix" line in config.yml doesn't work anymore.

What I changed:
- Added new HELP_HEADER option in config.yml
- Changed all 1.8 sounds to 1.12
- Fixed a few errors with the config

Commands:

• /trade - Opens the help menu
• /trade accept - accepts the current trade offer
• /trade ignore - ignores future trade offers.

Permissions:

• trade.trade - gives access to the /trade command
• trade.accept - gives access to /trade accept
• trade.ignore - gives access to /trade ignore
• trade.reload - gives access to /trade reload