Add space flexibility for nested queries

docs/tutorial/SearchService.md

...org/opengroup/osdu/search/util/AggregationParserUtil.java

.../java/org/opengroup/osdu/search/util/QueryParserUtil.java

...n/java/org/opengroup/osdu/search/util/SortParserUtil.java

...opengroup/osdu/search/util/AggregationParserUtilTest.java

...va/org/opengroup/osdu/search/util/SortParserUtilTest.java

...tqueries/expected/multilevel-nested-query-with-space.json

...sources/testqueries/expected/nested-query-with-space.json

...ch-core/src/test/resources/testqueries/valid-queries.json