Unified storage bugfix legacy folders getting first page (#109554)

* When creating a new continue token, it defaults to page 1. Also use constants for default limit and page number.

* Update tests for continue token.

* When listing legacy folders, the continue token will have all paging info in it. Simplifies paging logic and fixes bug when limit not specified.

* Adds regression test to ensure default page limit is enforced.

* remove test comment

pkg/registry/apis/folders/continue.go

@@ -14,9 +14,13 @@ type continueToken struct {
 	limit int64
 }
 
+const defaultPageLimit = 100
+const defaultPageNumber = 1
+
 func readContinueToken(options *internalversion.ListOptions) (*continueToken, error) {
 	t := &continueToken{
-		limit: 100, // default page size
+		limit: defaultPageLimit,  // default page size
+		page:  defaultPageNumber, // default page number
 	}
 	if options.Continue == "" {
 		if options.Limit > 0 {