Change quote-props rule to "consistent-as-needed"

[wincent]

I just got bitten by this while preparing this PR: liferay/liferay-js-themes-toolkit#247

Basically, given an object containing some version numbers properties:

{
  '6.2': true,
  '7.0': true,
  '7.1': true,
}

we currently have ESLint configured via "quote-props" to require quotes around property names "as-needed"; producing this:

{
  6.2: true,
  '7.0': true,
  7.1: true,
}

This looks pretty terrible. I noticed that Prettier didn't have an opinion on this, so I changed them all to skip the quotes:

{
  6.2: true,
  7.0: true,
  7.1: true,
}

of course, that is wrong too, because 7.0 actually gets stringified to '7', meaning the object is equivalent to:

{
  '6.2': true,
  '7': true,
  '7.1': true,
}

This breaks checks of the form if (object['7.0'] === true). So I added a lint suppression and put strings back on all the keys, but we should just configure ESLint to use "consistent-as-needed" instead. Via the docs:

requires quotes around all object literal property names if any name strictly requires quotes, otherwise disallows quotes around object property names