`useBraces` - add `asNeeded` option as stricter `preferNone`

[Squidgical]

Consider this code;

while (condition) yield aBigCall({
  the: "expression",
  spans: "many",
  lines,
})

when formatting with useBraces: "preferNone";

while (condition) {
  yield aBigCall({
    the: "expression",
    spans: "many",
    lines,
  })
}

however my desired output is the exact same as the input. My philosophy is;

• I should not write any code that is redundant
• statements whose bodies contain only one expression/statement do not need braces
• braces on such statements are redundant
• I should not write braces on such statements

It would be nice to have an option which refuses to add or keep braces if they only enclose a single expression, regardless of whether that expression spans 3 characters or a million lines.

To me, this is what preferNone means; "prefer to use no braces, unless the code would behave incorrectly without them."

The current implementation of preferNone seems to be; "prefer to [...] without them or the code matches one of these arbitrary cases." This isn't preferring none, but instead preferring a particular opinionated style.

---

I would like to request another option asNeeded which will only permit braces where strictly necessary for functionality, and will enforce that single-expression bodies are not braced.