Add command to show all blacklisted users

[AndrewEdgers]

For now there is only one way to check who's in the blacklist by looking into database table.

So adding this command will make bot more user friendly and it's just convenient.

You may use my solution:

    @blacklist.command(
        base="blacklist",
        name="show",
        description="Show the list of all blacklisted users.",
    )
    @checks.is_owner()
    async def blacklist_show(self, context: Context) -> None:
        """
        Shows the list of all blacklisted users.

        :param context: The hybrid command context.
        """
        async with aiosqlite.connect("database/database.db") as db:
            async with db.execute("SELECT * FROM blacklist") as cursor:
                blacklist = await cursor.fetchall()
        if len(blacklist) == 0:
            embed = discord.Embed(
                title="Blacklist",
                description="There are no blacklisted users.",
                color=0x6930C3
            )
            await context.send(embed=embed)
            return

        embed = discord.Embed(
            title="Blacklist",
            description="Here is the list of all blacklisted users.",

            color=0x6930C3
        )
        for user in blacklist:
            embed.add_field(
                name=f"ID: {user[0]}",
                value=f"<@{user[0]}>",
                inline=False
            )
        await context.send(embed=embed)

[kkrypt0nn]

Thanks a lot for the idea! It has been added as per v5.4.2, I also used that opportunity to fix some error messages issues with the other blacklisting related commands.