Improved analysis of plugin language performance comparisons

### Where is the problem?

https://docs.konghq.com/gateway/latest/plugin-development/pluginserver/performance/

### What happened?

The performance comparison on this page wasn't as useful as I had hoped.

### What did you expect to happen?

It's nice to have some comparison documented, but it would be more useful to provide the plugin code that was analyzed. Also having actual values on the y axis so we have better sense of the scale of performance we should expect and comparing it to the same thing written in lua.

I'm trying to decide if it's worth trying to build a plugin in another language besides lua. I have heard that the lua performance is better than any of the other languages, but I haven't seen any numbers actually comparing them.

### Code of Conduct and Community Expectations

- [X] I agree to follow this project's Code of Conduct
- [X] I agree to abide by the Community Expectations

Start with the performance comparison page at https://docs.konghq.com/gateway/latest/plugin-development/pluginserver/performance/. Review how the existing comparison was produced, then document the analyzed plugin code, add actual y-axis values, and include the same comparison for Lua so readers can assess expected performance.

Written by the indexing model from the issue text.