Use Discord name instead of tag for /msg sender

[Thedalek07]

Information

This PR fixes #5520.

Details

Proposed fix:

change event.getMember().getTag() in event.getMember().getName()
remove the #discriminator on username

Environments tested:

OS: Windows 11

Java version:

• Most recent Paper version (1.XX.Y, git-Paper-BUILD)
• CraftBukkit/Spigot/Paper 1.12.2
• CraftBukkit 1.8.8

Demonstration:

BEFORE

AFTER