Function dewildcard

src/compute-engine/boxed-expression/rules.ts:1472–1482

* Replace all occurrences of a wildcard in an expression with a the corresponding non-wildcard, e.g. `_x` -> `x`

(expr: Expression)

 * For each rule in the rule set that matches, return the full `RuleStep`
 * (replacement value with its provenance: the rule id in `because`, plus
 * `purpose`). Used by callers that keep a step trace (`explain`).
 *
 * @param rules
 */
export function matchAnyRulesWithSteps(
  expr: Expression,
  rules: BoxedRuleSet,
  sub: BoxedSubstitution,
  options?: Partial<ReplaceOptions>
): RuleStep[] {
  const results: RuleStep[] = [];

  const collect = (rule: BoxedRule): void => {
    // Matching a single rule against a large expression (e.g. a