[MM-56555] Patch commonmark to resolve unmentioned username

[cyberjam]

Summary

When a username that starts with number or period, underscore, dash is mentioned, the fullname doesn't appear. Only @username is displayed.

Ticket Link

Fixes #7755
JIRA: https://mattermost.atlassian.net/browse/MM-56555

Checklist

• Added or updated unit tests (required for all new features)
• Has UI changes
• Includes text changes and localization file updates
• Have tested against the 5 core themes to ensure consistency between them.

Device Information

This PR was tested on:

• Device Name: iPhone 11
• OS Version: iOS 17.0

Screenshots

Before	After

Release Note

NONE

ref : commonmark repo PR

[mattermost-build]

Hello @cyberjam,

Thanks for your pull request! A Core Committer will review your pull request soon. For code contributions, you can learn more about the review process here.

[mattermost-build]

This PR has been automatically labelled "stale" because it hasn't had recent activity.
A core team member will check in on the status of the PR to help with questions.
Thank you for your contribution!

[DAMHONGDUC]

thanks in advance