Elasticsearch Output Plugin: Add support for following http redirects

**Is your feature request related to a problem? Please describe.**

We were doing a migration from one elasticsearch instance to another hoping that a URL redirect would be all we would need to put in place to handle redirecting wild fluent bit instances that were still using the the legacy URL.

To our surprise, we discovered that the elasticsearch output plugin is not capable of following http redirects, resulting in the records getting dropped. This forced us to have to scramble to track down all the fluent bit instances and update their configurations to point to the new URL, resulting in data-loss during that time frame.

**Describe the solution you'd like**

It would be nice for the elasticsearch output plugin to following http redirects.