Add Elastic exporter compatibility with Elasticsearch version 8.x

[tchangz]

Feature description:
Being a fan of LoggerPlusPlus I would like to continue to use the Elastic exporter feature with a version 8 of Elasticsearch.

It seems the index creation from LoggerPlusPlus to elastic version 8.3.2 is working however no log is exported in the this index after (same configuration is fully working with a version 7.16.3). Making LoggerPlusPlus compatible with Elasticsearch 8.x version would be really usefull.

[CoreyD97]

Unfortunately it looks like the ElasticSearch API doesn't have any backwards compatibility, so this change will make the exporter incompatible with Elastic 7.x and below. Though, I think its more important to support the newest versions here rather than maintain backwards compatibility.

[303sec]

Given that support for 7.x is already supported by L++, would it be possible to add a UI element allowing users to select the Elastic version?

[CoreyD97]

Unfortunately not. It wouldn't be possible to deploy two versions of the same library here. Instead, I'd recommend upgrading to ES8 to use the new version of the exporter.