resolveAll static method
Resolves every built-in, skipping the ones that are unavailable.
Used by distribute doctor and distribute validate to show the user
what the placeholders will expand to.
Implementation
static Future<Map<String, String>> resolveAll() async {
final resolved = <String, String>{};
for (final name in _resolvers.keys) {
final value = await resolve(name);
if (value != null) resolved[name] = value;
}
return resolved;
}