The ngtsc partial evaluator previously would not handle an enum reference
inside a template string expression correctly. Enums are resolved to an
`EnumValue` type, which has a `resolved` property with the actual value.
When effectively toString-ing a `ResolvedValue` as part of visiting a
template expression, the partial evaluator needs to translate `EnumValue`s
to their fully resolved value, which this commit does.
PR Close#29062
a06824aef6