* all: run gofumpt
https://github.com/mvdan/gofumpt
The main appeal for me here is that my (and many other peoples')
editors run this on save, so doing a single diff here
keeps other diffs minimal.
* .github/workflows: add gofumpt checker
* add coverage for go proxy
* Refactor CLI flag name for allowed proxy addresses
* Refactor YAML schema to support multiple authorized keys and known hosts
* add testcases
* Refactor YAML schema to support multiple authorized keys and known hosts
* go fmt
* go fmt