Change the web application to have a unified font-family

### Describe the Bug

_A clear and concise description of what the bug is._
Some text in web app has font-family: Lato,'Helvetica Neue',Arial,Helvetica,sans-serif (e.g. `Session 1` in the Event page), while others have font-family: Inter,X-LocaleSpecific,sans-serif;

### Expected Behavior

_A clear and concise description of what you expected to happen._

We want just one font-family for all texts and it should be Inter,X-LocaleSpecific,sans-serif;

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I suspect the fix requires digging into semantic-ui-css/semantic-ui-react config to set the font-family.