Add ability to try to get templates from files or remotes#968

deepmap-marcinr merged 7 commits intooapi-codegen:masteroapi-codegen/oapi-codegen:masterfrom

deefdragon:deefdragon-user-templates-from-url-filedeefdragon/oapi-codegen:deefdragon-user-templates-from-url-fileCopy head branch name to clipboard