_sort can cause ChainedSearch to return zero results

[brendankowitz]

Description

Fixes bug where _sort can cause Chained Search not to return correct results.

Previously, the sort options from the chained search's SearchOption object was not cleared, causing the sorting options to be passed through to the chained sub-search, which are not valid.

SELECT r.resourceId, r.resourceTypeName
FROM root r
WHERE r.isSystem = @param0
AND r.resourceTypeName = @param1
AND EXISTS (SELECT VALUE si FROM si IN r.searchIndices WHERE si.p = @Param2 AND si.c = @param3)
AND r.isHistory = @param0
AND r.isDeleted = @param0
ORDER BY r.sort["birthdate"].l ASC

Related issues

Addresses #2344, AB#86544

Testing

Adds E2E regression test

FHIR Team Checklist

• Update the title of the PR to be succinct and less than 50 characters
• Add a milestone to the PR for the sprint that it is merged (i.e. add S47)
• Tag the PR with the type of update: Bug, Dependencies, Enhancement, or New-Feature
• Tag the PR with Azure API for FHIR if this will release to the Azure API for FHIR managed service (CosmosDB or common code related to service)
• Tag the PR with Azure Healthcare APIs if this will release to the Azure Healthcare APIs managed service (Sql server or common code related to service)
• Review squash-merge requirements

Semver Change (docs)

Patch

[namadabu]