[Frontend] Implemented Admin Route

[amlannandy]

Description

Implemented an Admin Route in the web app to protect the admin pages. Pages with admin routes can be accessed only by authenticated users with admin privilege.

Fixes #119

Type of change

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

N/A

Test Configuration:

• Google Chrome
• Windows 10

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules