Fix sorting of utilities that share multiple candidates

[thecrypticace]

Previously, when given a set of utilities or components that have multiple candidates on one of the rules, and sorting multiple sets of rules one after the other, we could cause the sort order of existing rules to be influenced.

For example, given the following components added by a plugin:

addComponents({
  '.x': { color: 'red' },
  '.a': { color: 'red' },

  // Note how this one has both `a` and `y` classes
  '.y .a': { color: 'red' },
})

And the following HTML:

<div class="x y"></div>
<div class="a"></div>

The prettier plugin sorts the first class list x y and returns x y. Then, it sorts a which ALSO has a matching rule containing y. These rules are shared internally and because of this the candidate would be replaced. Thus, when sorting again the order of x y would be flipped because it looked as if y did not have a known sort order (because that rule was now associated with a instead of y).

To work around this, in this PR we're cloning rules when sorting so the state is no longer shared and the order remains consistent.

Fixes tailwindlabs/prettier-plugin-tailwindcss#220
Fixes tailwindlabs/prettier-plugin-tailwindcss#221