[Enhancement] Regular expression (regex) support for excludedCommands list

[Xujiayao]

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Description

This increases the flexibility of the excludedCommands list, allowing users to set it freely.

Inspiration from Discord: (by @Janne252)

Hey! I think the line https://github.com/Xujiayao/Discord-MC-Chat/blob/master/src/main/java/com/xujiayao/discord_mc_chat/minecraft/MinecraftEventListener.java#L171 should also check for command == excludedCommand, .i.e.

for (String excludedCommand : CONFIG.generic.excludedCommands) {
    if (command.startsWith(excludedCommand + " ") || command == excludedCommand) {
        return;
    }
}

so that commands that don't have any arguments can also be ignored. Otherwise it's impossible to ignore commands that don't have any agruments, e.g. /list.

[Xujiayao]

The new excludedCommands list is:

"excludedCommands": [
  "\\/msg ([^@].*)",
  "\\/tell ([^@].*)",
  "\\/tellraw ([^@].*)",
  "\\/w ([^@].*)",
  "\\/teammsg (.*)",
  "\\/tm (.*)"
],

i.e. /tell @a Test will not be excluded, /tell Xujiayao Test will be excluded.

To exclude /list without (and only without) arguments, simply add \\/list to the list.

Included \\/teammsg (.*) and \\/tm (.*) in the list, which provides an example of normal excluding for other users.