Fix lint warnings

[psiinon]

The following rules were set to "warn" so that we could focus on more important issues, but these should all be fixed as well:

• [ ] no-negated-condition
• [ ] no-unused-vars
• [ ] prefer-destructuring
• [ ] unicorn/no-for-loop
• [ ] unicorn/prefer-includes
• [ ] unicorn/prefer-string-slice
• [ ] unicorn/filename-case
• [ ] unicorn/prefer-query-selector
• [ ] Unsafe assignment to innerHTML no-unsanitized/property - see FIXME in in display.js

The overrides are defined in https://github.com/zaproxy/zap-hud/blob/develop/package.json#L54-L63 (the lines may change in time)

[VitikaSoni]

@psiinon I want to fix some of these, could you please assign me?

[psiinon]

Assigned 😁