Improve emoji search on message input

[marc-casoliva]

Description:

When chatting, every time I want to use an emoji with a long/complex name (for example, 😜 ) I need to remember how this emoji name starts if I don't want to leave the keyboard.

I would like to be able to use the ":emoji_name" autocomplete feature like in the emoji menu search box, where is enough to remember the key point of the name to find the desired emoji (in the same example, "tongue" will show the 😜 emoji).

Thanks!

Server Setup Information:

• Version of Rocket.Chat Server: 0.60.4 34cd952
• Operating System: Linux 4.4.0-108-generic
• Deployment ID: TYCowHgdaFxnrLXpk
• Number of Running Instances: 1
• DB Replicaset Oplog: Active
• Node Version: v8.9.3