My use case is that I have a field which is storing IDs. Those IDs might be coming from different sources, but in general there might be noise. For example, there might be ID `000123` and I would like to configure normalizer which trims all prefix zeros:

```
"zeros_prefix_trim": {
  "type": "pattern_replace",
  "pattern": "^0+",
  "replacement": "",
  "all": false
}
```

But it seems this is not allowed. Not sure why, because `trim` filter itself works (after #27310, which has not been documented, BTW).
modules/analysis-common/src/main/java/org/elasticsearch/analysis/common/PatternReplaceTokenFilterFactory.java
private final Pattern pattern;
    private final String replacement;
    private final boolean all;
    public PatternReplaceTokenFilterFactory(IndexSettings indexSettings, Environment environment, String name, Settings settings) {
        super(name, settings);
        String sPattern = settings.get("pattern", null);
        if (sPattern == null) {
            throw new IllegalArgumentException("pattern is missing for [" + name + "] token filter of type 'pattern_replace'");
        }
        this.pattern = Regex.compile(sPattern, settings.get("flags"));
        this.replacement = settings.get("replacement", "");
        this.all = settings.getAsBoolean("all", true);
    }
    @Override
    public TokenStream create(TokenStream tokenStream) {
        return new PatternReplaceFilter(tokenStream, pattern, replacement, all);
    }
}