I don't think it's a database configuration issue because when I copy paste the exact same HTML code into a new page manually, MediaWiki shows all characters properly. Don't you think? See below image.

I am confident that mysql is now using the my.cnf with the following content:

That's right. In fact, for troubleshooting purposes, I am working with a single HTML file for now. And it is the one I posted above.

OK I have modified the my.conf as follows

I am using the default settings of mysql (not super familiar with it). I ran the commands on this page https://stackoverflow.com/questions/1049728/how-do-i-see-what-character-set-a-mysql-database-table-column-is and mysql returned Empty set (0.00 sec)

@Aklapper Thanks! Hope I have been thorough enough. If not please do let me know what I have missed.