Create a unit test format to test plugin configuration

[sspaink]

Plugins need a way to test the configuration to prevent regressions such as seen in this issue: #9413

Two possible approaches:

• Have a unit test parse the sample config from the README.md associated with the plugin, and attempt to load it and compare it to the struct defined in the go file
• Have the plugin generate the go struct and README.md from a sample config, requiring any updates to the config to be in one place