Add ContextMenuCommandBuilder support (and more!)

A couple of nice additions here;

• ContextMenuCommandBuilder builders can now be defined with command handlers.

  const {  ApplicationCommandType, SlashCommandRegistry } = require('discord-command-registry');
  new SlashCommandBuilder().addContextMenuCommand(command => command
    .setName('menu-option')
    .setType(ApplicationCommandType.Message)
    .setHandler(interaction => interaction.reply('selected something from the menu!'))
  )

• @discordjs/builders defined utility methods, such as bold for dressing up messages. These are all now forwarded through this library, so they can be directly imported.

  const { bold } = require('discord-command-registry');

• Add new option helper for Emojis. Like Options.getApplication(...), you use this by defining string option, then using Option.getEmoji(interaction, 'opt_name') in your handler.
• Option resolvers now support an optional third required argument to be in line with the ones built into Discord.js. Like the built-in ones, these default to false. Example: Option.getEmoji(interaction, 'opt_name', true).