Time to write another story on `@apply`...

When we write code like this:

```css
.a {
  @apply b;
}

.b {
  @apply uppercase;
  color: red;
}
```

Then we create 2 Nodes in our context to keep track of. One has
identifier `a`, the other has identifier `b`. However, when we have an
`@apply` and it contains multiple declarations/atrules, then we have to
split up the (aka partition) node into multiple nodes so that we can
guarantee the correct expected sort order.

This means that the above example technically looks like this:

```css
.a {
  @apply b;
}

.b {
  @apply uppercase;
}

.b {
  color: red;
}
```

If this was your input, then we would still have 1 node for identifier
'a', but we would have 2 nodes for identifier 'b'.

As mentioned earlier, this is important to guarantee the correct order,
here is an example:

```css
.b {
  @apply md:font-bold xl:font-normal; /* Here we can sort by our
  internal rules. This means that the `md` comes before `xl`. */
}
```

... however

```css
.b {
  @apply xl:font-normal; /* This now exists _before_ the example below */
}

.b {
  @apply md:font-bold; /* Because we respect the order of the user's css */
}
```

So to guarantee the order when doing this:
```css
.b {
  @apply xl:font-normal;
  @apply lg:font-normal;
}
```

We also split this up into 2 nodes like this:
```css
.b {
  @apply xl:font-normal;
}
.b {
  @apply lg:font-normal;
}
```

The tricky part is that now only 1 empty `.b` node exists in our context
because we partitioned the orginal node into multiple nodes and moved
the children to the new nodes and because they are new nodes it means
that they have a different identity.

This partitioning used to happen in the expandApplyAtRules code, but
this is a bit too late because the context has already been filled at
this time. Instead, we move the code more to the front, as if you wrote
those separated blocks yourself. Now the code to inject those nodes into
the context happens in a single spot instead of multiple places.

Another good part about this is that we have better consistency between
each layer because it turns out that these two examples generated
different results...

```css
.a {
  @apply b;
}
.b {
  @apply uppercase;
  color: red;
}
```

... is different compared to:

```css
@tailwind components;
@layer components {
  .a {
    @apply b;
  }
  .b {
    @apply uppercase;
    color: red;
  }
}
```

Even if both `a` and `b` are being used in one of your content paths...
Yeah.. *sigh*

This has been fixed already