### Description

Our most common aggregations should be optimized for single-valued fields. In general, our aggregations look like this:

```java
    @Override
    public LeafBucketCollector getLeafCollector(LeafReaderContext ctx, LeafBucketCollector sub) throws IOException {
        if (valuesSource == null) {
            return LeafBucketCollector.NO_OP_COLLECTOR;
        }
        SortedNumericDocValues values = valuesSource.longValues(ctx);
        return new LeafBucketCollectorBase(sub, values) {
            @Override
            public void collect(int doc, long owningBucketOrd) throws IOException {
                if (values.advanceExact(doc)) {
                    int valuesCount = values.docValueCount();
                    for (int i = 0; i < valuesCount; ++i) {
                        long value = values.nextValue();
                        // do something with value
                    }
                }
            }
        };
    }
```

The idea consists of optimizing for single-valued fields by unwrapping the single-valued doc-value iterator:

```java
    @Override
    public LeafBucketCollector getLeafCollector(LeafReaderContext ctx, LeafBucketCollector sub) throws IOException {
        if (valuesSource == null) {
            return LeafBucketCollector.NO_OP_COLLECTOR;
        }
        SortedNumericDocValues values = valuesSource.longValues(ctx);
        NumericDocValues singleValues = DocValues.unwrapSingleton(values); // or FieldData.unwrapSingleton for doubles
        if (singleValues != null) {
            return new LeafBucketCollectorBase(sub, values) {
                @Override
                public void collect(int doc, long owningBucketOrd) throws IOException {
                    if (singleValues.advanceExact(doc)) {
                        long value = singleValues.longValue();
                        // do something with value
                    }
                }
            };
        } else {
            return new LeafBucketCollectorBase(sub, values) {
                @Override
                public void collect(int doc, long owningBucketOrd) throws IOException {
                    if (values.advanceExact(doc)) {
                        int valuesCount = values.docValueCount();
                        for (int i = 0; i < valuesCount; ++i) {
                            long value = values.nextValue();
                            // do something with value
                        }
                    }
                }
            };
        }
    }
```

The `terms` aggregation already does this, and e.g. `min` and `max` aggregations use similar tricks that also help optimize the single-valued case. But `date_histogram`, which is one of our most common aggregations, doesn't. Let's specialize the single-value case for date histograms too?
server/src/test/java/org/elasticsearch/search/aggregations/bucket/range/RangeAggregatorTests.java
}
    public void testNotFitIntoDouble() throws IOException {
        MappedFieldType fieldType = new NumberFieldMapper.NumberFieldType(
            NUMBER_FIELD_NAME,
            NumberType.LONG,
            true,
            false,
            true,
            false,
            null,
            Collections.emptyMap(),
            null,
            false,
            null
        );
        long start = 2L << 54; 
        RangeAggregationBuilder aggregationBuilder = new RangeAggregationBuilder("range").field(NUMBER_FIELD_NAME)
            .addRange(start, start + 50)
            .addRange(start + 50, start + 100)
            .addUnboundedFrom(start + 100);
        testCase(aggregationBuilder, new MatchAllDocsQuery(), iw -> {
            for (long l = start; l < start + 150; l++) {
                iw.addDocument(List.of(new SortedNumericDocValuesField(NUMBER_FIELD_NAME, l), new LongPoint(NUMBER_FIELD_NAME, l)));
            }
        }, (Consumer<InternalRange<?, ?>>) range -> {
            List<? extends InternalRange.Bucket> ranges = range.getBuckets();
            assertThat(ranges, hasSize(3));
            
            assertThat(ranges.stream().mapToLong(InternalRange.Bucket::getDocCount).toArray(), equalTo(new long[] { 44, 48, 58 }));
            assertTrue(AggregationInspectionHelper.hasValue(range));