Custom emojis: does not handle correctly emojis with overlapping names

[JohnXLivingston]

Describe the bug

If you had some custom emojis with names that overlap (for example test and test1), the result is buggy.
The shorter short name takes precedences, and you got the test emoji with a 1 after it.

To Reproduce
Steps to reproduce the behavior:

1. define some custom emojis, with shortname test and test1
2. try to use test1 in a chat

Expected behavior

Longest shortname should be resolved first

Screenshots

In the following screenshot, i have penguin and penguin3 as shortnames, and you can see the 3 that appears:

I did not find how to correct the bug, there are some code parts that i'm not familiar with.