…17308)

This PR adds suggestions to CSS based functional utilities when the
`--spacing(…)` function is used.

Given this CSS:

```css
@import "tailwindcss";

@theme {
  --spacing: 0.25rem;
  --spacing-custom: 123px;
}

@Utility with-custom-spacing-* {
  size: --value(--spacing);
}

@Utility with-integer-spacing-* {
  size: --spacing(--value(integer));
}

@Utility with-number-spacing-* {
  size: --spacing(--value(number));
}
```
    
And this HTML:
    
```html
<div class="with-custom-spacing-custom"></div>
<div class="with-custom-spacing-0"></div>
<div class="with-custom-spacing-0.5"></div>
<div class="with-custom-spacing-1"></div>
<div class="with-custom-spacing-1.5"></div>

<div class="with-integer-spacing-custom"></div>
<div class="with-integer-spacing-0"></div>
<div class="with-integer-spacing-0.5"></div>
<div class="with-integer-spacing-1"></div>
<div class="with-integer-spacing-1.5"></div>

<div class="with-number-spacing-custom"></div>
<div class="with-number-spacing-0"></div>
<div class="with-number-spacing-0.5"></div>
<div class="with-number-spacing-1"></div>
<div class="with-number-spacing-1.5"></div>
```
    
Play: https://play.tailwindcss.com/tYDaSNiNtS


Then you will see the following suggestions:

```json
[
  "with-custom-spacing-custom",

  "with-integer-spacing-0",
  "with-integer-spacing-1",
  "with-integer-spacing-2",
  "with-integer-spacing-3",
  "with-integer-spacing-4",
  "with-integer-spacing-5",
  "with-integer-spacing-6",
  "with-integer-spacing-7",
  "with-integer-spacing-8",
  "with-integer-spacing-9",
  "with-integer-spacing-10",
  "with-integer-spacing-11",
  "with-integer-spacing-12",
  "with-integer-spacing-14",
  "with-integer-spacing-16",
  "with-integer-spacing-20",
  "with-integer-spacing-24",
  "with-integer-spacing-28",
  "with-integer-spacing-32",
  "with-integer-spacing-36",
  "with-integer-spacing-40",
  "with-integer-spacing-44",
  "with-integer-spacing-48",
  "with-integer-spacing-52",
  "with-integer-spacing-56",
  "with-integer-spacing-60",
  "with-integer-spacing-64",
  "with-integer-spacing-72",
  "with-integer-spacing-80",
  "with-integer-spacing-96",

  "with-number-spacing-0",
  "with-number-spacing-0.5",
  "with-number-spacing-1",
  "with-number-spacing-1.5",
  "with-number-spacing-2",
  "with-number-spacing-2.5",
  "with-number-spacing-3",
  "with-number-spacing-3.5",
  "with-number-spacing-4",
  "with-number-spacing-5",
  "with-number-spacing-6",
  "with-number-spacing-7",
  "with-number-spacing-8",
  "with-number-spacing-9",
  "with-number-spacing-10",
  "with-number-spacing-11",
  "with-number-spacing-12",
  "with-number-spacing-14",
  "with-number-spacing-16",
  "with-number-spacing-20",
  "with-number-spacing-24",
  "with-number-spacing-28",
  "with-number-spacing-32",
  "with-number-spacing-36",
  "with-number-spacing-40",
  "with-number-spacing-44",
  "with-number-spacing-48",
  "with-number-spacing-52",
  "with-number-spacing-56",
  "with-number-spacing-60",
  "with-number-spacing-64",
  "with-number-spacing-72",
  "with-number-spacing-80",
  "with-number-spacing-96"
]
```

This is because `--spacing(--value(number))` will include all default
spacing scale suggestions we use. And `--pacing(--value(integer))` will
include the same list but without the floating point numbers.

Follow up PR for: #17304