fix: Use a HashRouter to make the explorer work on Netlify

[alainncls]

What does this PR do?

Related ticket

Fixes #460

Type of change

• Chore
• Bug fix
• New feature
• Documentation update

Check list

• Unit tests for any smart contract change
• Contracts and functions are documented

[netlify]

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[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (d9507b8) 94.24% compared to head (1fa5181) 94.24%.

Additional details and impacted files

@@           Coverage Diff           @@
##              dev     #459   +/-   ##
=======================================
  Coverage   94.24%   94.24%           
=======================================
  Files          19       19           
  Lines         313      313           
  Branches       68       68           
=======================================
  Hits          295      295           
  Misses          9        9           
  Partials        9        9           

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