Add support for localPlugins

[mloiseleur]

Description

Only remote plugins are natively supported FTM.

The localPlugins options should also be supported, with a working example

[zalbiraw]

For now you can add these values to our chart to enable to localPlugins:

additionalArguments = [
  "--experimental.localPlugins.headertoquery.moduleName=github.com/zalbiraw/headertoquery"
]

volumes = [
  {
    type = "volume",
    name = "header-to-query-plugin"
    mountPath = "/plugins-local/src/github.com/zalbiraw/headertoquery/"
  }
]