fix(ls): provide completion items with proper filtering

Before this change, completion items were only
provided if they started by the filtered text.

With this change, completion items are provided
if they include filtered text.

Refs swagger-api/swagger-editor#3216

packages/apidom-ls/src/services/completion/completion-service.ts

@@ -781,7 +781,7 @@ export class DefaultCompletionService implements CompletionService {
             */
             item.filterText = text.substring(nodeSourceMap.offset, nodeSourceMap.endOffset!);
 
-            if (word && word.length > 0 && unquotedOriginalInsertText?.startsWith(word)) {
+            if (word && word.length > 0 && unquotedOriginalInsertText?.includes(word)) {
               collector.add(item);
             } else if (!word) {
               collector.add(item);