feat(preset-mini): support size-* shorthand

[Mini-ghost]

This PR adds the size-* shorthand to support setting both width and height in a class.

Example:

/* <div class="size-[calc(1000px-4rem)]></div>  */
.size-\[calc\(1000px-4rem\)\] {
  width: calc(1000px - 4rem);
  height: calc(1000px - 4rem);
}

/* <div class="size-[var(--something)]></div> */
.size-\[var\(--something\)\] {
  width: var(--something);
  height: var(--something);
}

/* <div class="size-10></div>  */
.size-10 {
  width: 2.5rem;
  height: 2.5rem;
}

/* <div class="size-max-10></div>  */
.size-max-10 {
  max-width: 2.5rem;
  max-height: 2.5rem;
}

/* <div class="size-min-10></div>  */
.size-min-10 {
  min-width: 2.5rem;
  min-height: 2.5rem;
}

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[chu121su12]

How about moving the rule before the size-w/h so size-w-10 can override size-10?

[Mini-ghost]

Thank you for the reminder, this is indeed very important.