Refactor AdminDashboard component to use Material-UI Typography for h…

[chukalicious]

Fixes #1671

What changes did you make and why did you make them ?

• the task required the change of regular html elements for their MUI equivalents, if applicable. Hence, I imported the Typography component from MUI and implemented it in place of the h1 component in the line 390. I implemented the variant and component properties as "h1".
• It appears some formatting changes were also performed by my formatting extension.

Screenshots of Proposed Changes Of The Website (if any, please do not screen shot code changes)

Visuals before changes are applied

Visuals after changes are applied