Port Legacy Commands to Slash Commands

[zekroTJA]

[This Issue is linked to #287]

⚠️ Attention
I am currently hardly working on porting most of the commands. If you want to participate, please comment below the issue which commands you want to port. Otherwise, It could happen that your work needs to be discarded because I have already ported the command meanwhile.

In order to apply the new slash command system, all current legacy commands are required to be ported to slash commands.

The following list tracks the current status of ported commands.

CHAT

• [x] chanstats
• [x] exec
• [x] guild
• [x] karma
• [x] quote
• [x] say
• [x] tag
• [x] twitch
• [x] user
• [x] vote

ETC

• [x] bug
• [x] id
• [x] login
• [x] snowflake
• [x] stats

GENERAL

• [x] help (obsolete)
• [x] info

GLOBAL ADMIN

• [x] game
• [x] maintenance

GUILD ADMIN

• [x] backup

GUILD CONFIG

• [x] autorole
• [x] color
• [x] joinmsg
• [x] leavemsg
• [x] modlog
• [x] perms
• [x] prefix (obsolete)
• [x] starboard
• [x] voicelog

MODERATION

• [x] ban
• [x] clear
• [x] ghost
• [x] inv
• [x] kick
• [x] lock
• [x] ment (obsolete)
• [x] mute
• [x] mvall
• [x] notify
• [x] report