Add removeEmoji function to mail services

[nicoaravena]

This PR fix an error ocurred when an item bought from the store goes with an emoji inside the message.

Solution proposed

• Remove all emoji coming in the item message.

How to test

• Go to https://getemoji.com/
• Buy some item from the store and add one emoji to the message

[Eronox]

Tested and works fine, however since we can assume everyone is using modern browsers and OS nowadays i'd vote for converting them to unicode to preserve them

[nicoaravena]

I don't know how the client manage the emojis, if works fine all this thing ingame and doesn't broke them, the I can do a new aproach

[Helias]

I would like to merge this asap, because it's a bit urgent, if anyone read this can break the db, we could make the improvement in another PR

[nicoaravena]

@Helias just add your suggestion.