Fix eslint issues reported by Gitlab CI

The automated fix patch generated by eslint has fixed some but not all of the issues.

The remaining issues are:

/builds/project/form_state_empty/web/modules/custom/form_state_empty/js/state-empty.js
  10:29  error  Expected '===' and instead saw '=='    eqeqeq
  14:13  error  Prefer HTMLInputElement#value to .val  no-jquery/no-val
✖ 2 problems (2 errors, 0 warnings)

Eslint is now happy in Github CI.

A second pair of eyes on the JS changes would be appreciated!