[Helm] Support all options for Elastic Agent Standalone Outputs

**Describe the enhancement:**
Currently the Elastic Agent Helm chart only supports Elasticsearch type outputs. Ideally it should support all 3 output types(elasticsearch, kafka, and logstash). Additionally it does not support all of the possible configuration options for Elasticsearch such as presets to allow tuning of the output.

**Describe a specific use case for the enhancement or feature:**
Elastic Agent needs to send data to kafka or logstash. Additionally Elastic Agent has performance issues and needs further tuning to optimize EPS.

**What is the definition of done?**
Support for all elastic agent output options with example values.yaml files for all output options. This should also include the rendered output for these examples.

Start by locating the Elastic Agent Helm chart, its values.yaml examples, and the mechanism used to produce rendered output. Review how Elasticsearch outputs are currently represented, then compare the required Elasticsearch, Kafka, and Logstash options against the chart configuration. Done means each output type has an example values.yaml and corresponding rendered output, including Elasticsearch presets.

Written by the indexing model from the issue text.