**Describe the bug**

It is not possible to search for dates with comparators, e.g. to exclude a date range.

**To Reproduce**
Steps to reproduce the behavior:
1. Spin up FHIR server, load synthea data
2. Search `/Patient?birthdate=ge1980-01-01,lt1970-01-01`, i.e. not the 70s.
3. Returns:
```
{
"resourceType": "OperationOutcome",
"id": "88972a44-e8f0-4773-97b4-b6780c2f5bff",
"issue": [
{
"severity": "error",
"code": "forbidden",
"diagnostics": "Comparator is not supported when multiple values are specified using OR search parameter."
}
]
}
```
**Expected behavior**

Should return all patients not born in the 70s.

**Actual behavior**

Rejects search.

**Additional information**

HAPI does not support this:

```
GET http://hapi.fhir.org/baseR4/Patient?birthdate=ge1980-01-01,lt1970-01-01
````

returns:

```
{
"resourceType": "OperationOutcome",
"text": {
"status": "generated",
"div": "

DateRange parameter does not suppport OR queries

Vonk supports this search:

```
GET https://vonk.fire.ly/Patient?birthdate=ge1980-01-01,lt1970-01-01
```

Start by reproducing the FHIR search against /Patient?birthdate=ge1980-01-01,lt1970-01-01 with the Synthea data setup described. Trace the handling of comparator values combined with OR search parameters, and consider the issue done when the query returns patients born outside the 1970s instead of rejecting the search.

Written by the indexing model from the issue text.