[cosmos] Fix CountIf aggregation and add full-text query tests (#35054)

### Packages impacted by this PR
@azure/cosmos

### Issues associated with this PR


### Describe the problem that is addressed by this PR

This PR -
1. adds test cases for full text search.
2. Fixes COUNTIF aggregation to use `CountAggregator` instead of
`StaticValueAggregator`.
This ensures that partial results from multiple partitions or batches
are correctly summed, producing accurate results for COUNTIF queries.

### What are the possible designs available to address the problem? If
there are more than one possible design, why was the one in this PR
chosen?


### Are there test cases added in this PR? _(If not, why?)_


### Provide a list of related PRs _(if any)_


### Command used to generate this PR:**_(Applicable only to SDK release
request PRs)_

### Checklists
- [ ] Added impacted package name to the issue description
- [ ] Does this PR needs any fixes in the SDK Generator?** _(If so,
create an Issue in the
[Autorest/typescript](https://github.com/Azure/autorest.typescript)
repository and link it here)_
- [ ] Added a changelog (if necessary)

---------

Co-authored-by: Aditishree . <adlnu@microsoft.com>

Author: aditishree1

sdk/cosmosdb/cosmos/review/cosmos.api.md

@@ -27,7 +27,7 @@ export interface Agent {
 }
 
 // @public (undocumented)
-export type AggregateType = "Average" | "Count" | "Max" | "Min" | "Sum" | "MakeSet" | "MakeList";
+export type AggregateType = "Average" | "Count" | "Max" | "Min" | "Sum" | "MakeSet" | "MakeList" | "CountIf";
 
 // @public
 export class AzureKeyVaultEncryptionKeyResolver implements EncryptionKeyResolver {

sdk/cosmosdb/cosmos/src/queryExecutionContext/Aggregators/index.ts

@@ -23,6 +23,7 @@ export function createAggregator(
     case "Average":
       return new AverageAggregator();
     case "Count":
+    case "CountIf":
       return new CountAggregator();
     case "Max":
       return new MaxAggregator();

sdk/cosmosdb/cosmos/src/request/ErrorResponse.ts

@@ -88,7 +88,15 @@ export interface HybridSearchQueryInfo {
 
 export type GroupByExpressions = string[];
 
-export type AggregateType = "Average" | "Count" | "Max" | "Min" | "Sum" | "MakeSet" | "MakeList";
+export type AggregateType =
+  | "Average"
+  | "Count"
+  | "Max"
+  | "Min"
+  | "Sum"
+  | "MakeSet"
+  | "MakeList"
+  | "CountIf";
 
 export interface GroupByAliasToAggregateType {
   [key: string]: AggregateType;

sdk/cosmosdb/cosmos/test/public/functional/NonStreamingQueryPolicy.spec.ts

@@ -559,8 +559,7 @@ async function executeQueryAndVerifyOrder(
   assert.equal(count, size);
 }
 
-// Skipping these tests as they are not supported by public emulator
-describe.skip("Full text search feature", async () => {
+describe("Full text search feature", async () => {
   let database: Database;
 
   beforeAll(async () => {