This PR resolves #8946 according to the interface described in #8946 (comment)

Examples

gh repo license list

gh repo license view <license>

gh repo gitignore list

gh repo gitignore view <gitignore-template>

Notes

• This PR moves and exports existing methods listLicenseTemplates and listGitIgnoreTemplates found here:

  cli/pkg/cmd/repo/create/http.go

  Lines 342 to 362 in d645fd4

  	// listGitIgnoreTemplates uses API v3 here because gitignore template isn't supported by GraphQL yet.
  	func listGitIgnoreTemplates(httpClient *http.Client, hostname string) ([]string, error) {
  	var gitIgnoreTemplates []string
  	client := api.NewClientFromHTTP(httpClient)
  	err := client.REST(hostname, "GET", "gitignore/templates", nil, &gitIgnoreTemplates)
  	if err != nil {
  	return []string{}, err
  	}
  	return gitIgnoreTemplates, nil
  	}
  	// listLicenseTemplates uses API v3 here because license template isn't supported by GraphQL yet.
  	func listLicenseTemplates(httpClient *http.Client, hostname string) ([]api.License, error) {
  	var licenseTemplates []api.License
  	client := api.NewClientFromHTTP(httpClient)
  	err := client.REST(hostname, "GET", "licenses", nil, &licenseTemplates)
  	if err != nil {
  	return nil, err
  	}
  	return licenseTemplates, nil
  	}

  to queries_repo.go. I felt this made the most sense since gh repo create uses these methods as well.
• I chose to go with table output for the list commands rather than just dumping out a list. Even thought gitignore list is a single column, I felt it would make sense to use the same tableprinter anyway.
• You may notice that this PR renames shared to format in pkg/cmd/repo/create/create.go - this is because I had originally missed that there were many queries in queries_repo.go; instead of using queries_repo.go, I had implemented queries in a package under shared, which prompted me to split shared into format and queries to better organize the code. However, I later removed queries when I realized about queries_repo.go, but decided to leave format as a changed package to align more closely with the package structure found in some other examples like https://github.com/cli/cli/tree/d645fd4f0066d96b1e5ef37089192f0d33ba9b84/pkg/cmd/project/shared/format This was reversed.

Feedback

I would love constructive feedback on anything, but I am particularly interested in:

• Did I miss any testing opportunities?
• Comments about the mild restructure and migration of listing functions
• Do you agree/disagree with the rename of the shared package to format? See Notes section above for more info.
  This was reversed.