fix: hide autocomplete on send button press

[Rohit3523]

Proposed changes

This PR fixes an issue where the autocomplete menu for user mentions @ or emojis : does not hide when a message is sent without selecting any suggestion from the menu. The fix ensures that the autocomplete menu is properly dismissed when the message is sent, providing a smoother user experience.

Issue(s)

N/A

How to test or reproduce

1. Open any channel or direct message.
2. Type @roh or :smi to trigger the autocomplete menu.
3. Without selecting any suggestion, press the send button.
4. Observe the autocomplete menu after sending the message.

Screenshots

Before	After
https://github.com/user-attachments/assets/2fb48c4a-575f-491c-87f1-a09a51cb4190	https://github.com/user-attachments/assets/28f040ff-ab69-4b83-8db2-9f97812e5e31

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• Improvement (non-breaking change which improves a current function)
• New feature (non-breaking change which adds functionality)
• Documentation update (if none of the other choices apply)

Checklist

• I have read the CONTRIBUTING doc
• I have signed the CLA
• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works (if applicable)
• I have added necessary documentation (if applicable)
• Any dependent changes have been merged and published in downstream modules