Updated all dependencies except eslint

[JonasDov]

• Updated all dependencies to latest versions.
• Updated all packages to esm instead of cjs as chai v5 supports only esm.
• Removed webpack and added vite.
• Removed chai, mocha and jest packages from e2e tests.
• Added .env file with client id, since users can see it anyway. This allows running both: #local and #web tests on the pipeline.

[grigasp]

I looked at the fonts situation and found that we're not using "Open Sans" at all since switching to itwinui-react version 3. That means we unnecessarily download the "Open Sans" font... IMO, we can just remove the font optimization stuff:

• remove app/frontend/public/fonts,
• remove the "Optimizing fonts" section from CONTRIBUTING.md.

[JonasDov]

I looked at the fonts situation and found that we're not using "Open Sans" at all since switching to itwinui-react version 3. That means we unnecessarily download the "Open Sans" font... IMO, we can just remove the font optimization stuff:

• remove app/frontend/public/fonts,
• remove the "Optimizing fonts" section from CONTRIBUTING.md.

Thanks for looking into it.
Removed