Validate OAuth Redirect URIs (#32643)

This fixes a TODO in the code to validate the RedirectURIs when adding
or editing an OAuth application in user settings.

This also includes a refactor of the user settings tests to only create
the DB once per top-level test to avoid reloading fixtures.

modules/validation/binding_test.go

@@ -27,6 +27,7 @@ type (
 	TestForm struct {
 		BranchName   string `form:"BranchName" binding:"GitRefName"`
 		URL          string `form:"ValidUrl" binding:"ValidUrl"`
+		URLs         string `form:"ValidUrls" binding:"ValidUrlList"`
 		GlobPattern  string `form:"GlobPattern" binding:"GlobPattern"`
 		RegexPattern string `form:"RegexPattern" binding:"RegexPattern"`
 	}