prompt to display and add local ollama keys to account (#3717)

- return descriptive error messages when unauthorized to create blob or push a model
- display the local public key associated with the request that was denied

types/errtypes/errtypes.go

@@ -0,0 +1,18 @@
+// Package errtypes contains custom error types
+package errtypes
+
+import (
+	"fmt"
+	"strings"
+)
+
+const UnknownOllamaKeyErrMsg = "unknown ollama key"
+
+// TODO: This should have a structured response from the API
+type UnknownOllamaKey struct {
+	Key string
+}
+
+func (e *UnknownOllamaKey) Error() string {
+	return fmt.Sprintf("unauthorized: %s %q", UnknownOllamaKeyErrMsg, strings.TrimSpace(e.Key))
+}