Remove jaeger, zipkin, kafka, testbed components

[bogdandrutu]

Link to tracking Issue: #3474

Signed-off-by: Bogdan Drutu bogdandrutu@gmail.com

[bcdady]

Hello @Aneurysm9, @bogdandrutu, et. al.
It seems that (re)moving these "contrib" components has broken some of their links in the Registry.
For example: viewing the list of available Receivers includes Kafka Collector Receiver, which ends up at a GitHub 404 page.
It appears this has happened before. I can open an issue and submit a PR at opentelemetry.io

[luckydonald]

Maybe a link in the README of that examples folder to the contrib git would be a good thing, because I had to dig through the commits to find the commit deleting that folder.

It would also be helping references like https://gist.github.com/darinpope/e762417311aa0621697a98fa795991f9 to be easily reproduced with the other ("new") repo's address, as this and #3999, removed the demo folder without an easy to find explanation.

[FarhanSajid1]

Could the examples in this repo be updated? I set this code up, and ran the docker container only to find out that the exporter logic had changed

https://github.com/open-telemetry/opentelemetry-go/tree/main/example/otel-collector/k8s

2022/01/02 04:45:37 collector server run finished with error: cannot unmarshal the configuration: unknown exporters type "jaegar" for "jaegar"