Usernames without nicknames in logs are duplicated

[sando]

Checklist

• I'm reporting a problem with Chatterino
• I've verified that I'm running the most recent nightly build or stable release
• I've looked for my problem on the wiki
• I've searched the issues and pull requests for similar looking reports

Describe your issue

If a user doesn't have a nickname set, their username is duplicated in chat logging. See example:

# Current behaviour:
[16:07:31] praxis099  praxis099: bag for cup but no cup
[16:07:44] beyson2301(龍亨街市) 龍亨街市 beyson2301: BBQ in 31 degree celsius monkaS

# With nickname set ("streamelements" set to "se"):
[18:47:29] se  streamelements: Posture check SwiftRage

# Previous behaviour: 
[15:40:19]  koromochii: KEKW
[15:40:20] ダスビーター das_beater: POGSPIN

Appears to be an unintentional side-effect due to the way #4663 was implemented (logging uses the search text of the message). IMO, nicknames don't really belong in chatlogs, but if we decide to include them, they probably shouldn't double-up like that.

Screenshots

No response

OS and Chatterino Version

Chatterino Nightly 2.4.4 (commit 53b044c) built on 2023-06-18 with Qt 6.5.0, MSVC 193632532 Running on Windows 11 Version 23H2, kernel: 10.0.25381