Allow field names with dots

[sothawo]

This PR adds the possbility to to define a custom field name in Elasticsearch that contains dots, for example:

@Nullable
@Field(name = "dotted.text", type = FieldType.Text)
private String dottedText;

terminology

dfn means dotted field name

field mapping

It is possible to send a mapping with a dfn, and Spring Data Elasticsearch will do so for such a field:

{
	"mappings": {
		"properties": {
			"dotted.field": {
				"type": "text"
			}
		}
	}
}

When retrieving the mapping, it is returned like nested object properties:

{
	"indexname": {
		"mappings": {
			"properties": {
				"dotted": {
					"properties": {
						"field": {
							"type": "text"
						}
					}
				}
			}
		}
	}
}

The same happens when a document with a dfn is sent to Elasticsearch directly without using Spring Data Elasticsearch.

Possible queries

A property that has a dfn name can be queried with:

@Query annotation:

@Query("""
	{
		"match": {
		"dotted.text": {
			"query": "?0"
			}
		}
	}
	""")
SearchHits<Foo> searchByDottedText(String text);
	}

CriteriaQuery:

return operations.search(CriteriaQuery.builder(
	Criteria.where("dottedText").is(text))
	.build(), Foo.class);

NativeQuery:

return operations.search(NativeQuery.builder()
	.withQuery(QueryBuilders.match(b -> b.field("dotted.text").query(text)))
	.build(), Foo.class);

Name based query:

SearchHits<Foo> searchByDottedText(String text);

The name based query works, becaus the java property has the name dottedField, what would not work would be findByDotted_Text.

Closes #2502