Issue with Cyrillic Words Highlighting

Description:

There's an issue with the highlighting functionality for Cyrillic words. When adding Russian words to Preferences > Highlights > Highlights word settings, these words do not get highlighted in the chat if they are not at the beginning of a sentence. This behavior is different from the highlighting of English words, which get highlighted regardless of their position in the sentence.

Steps to reproduce:

1. Open the Rocket.Chat desktop client.
2. Navigate to Preferences > Highlights.
3. Add a word in Russian (e.g., "тест") to the Highlights word list.
4. Send a message in any chat where the Russian word is not at the beginning of the sentence (e.g., "Это тест сообщения").
5. Observe that the Russian word is not highlighted in the message.

Expected behavior:

Russian words added to Highlights should be highlighted regardless of their position in the sentence, similar to the behavior for English words.

Actual behavior:

Russian words are only highlighted when they are at the beginning of the sentence.

Server Setup Information:

• Version of Rocket.Chat Server: 6.8.0
• Operating System: Linux
• Deployment Method: docker
• Number of Running Instances: 20
• DB Replicaset Oplog: Yes
• NodeJS Version: 14.21.3
• MongoDB Version: 5.0.21 / wiredTiger

Client Setup Information

• Desktop App or Browser Version: Rocket.Chat.Electron 3.9.9, Rocket.Chat.Electron 3.9.15
• Operating System: Microsoft Windows 10

Additional context

This issue affects users who communicate frequently in Russian or any other language using Cyrillic script, causing an inconsistent user experience. Any help in resolving this issue would be greatly appreciated.

Start in the Rocket.Chat desktop client's Preferences > Highlights flow and reproduce the issue with the Russian word "тест" in a sentence. Trace the highlight matching behavior for Cyrillic text and compare it with English matching; done means the word is highlighted regardless of its position, with the behavior verified in the reported client setup.