Option to disable error on duplicate type registration

[kasefuchs]

get_it now supports registering the same type multiple times using enableRegisteringMultipleInstancesOfOneType for later use with getAll. I think it would be useful to add an option to InjectableInit that would turn off the error when registering duplicate types.

injectable/injectable_generator/lib/generators/injectable_config_generator.dart

Lines 304 to 306 in 00974a8

	throwBoxed(
	'${dep.typeImpl} [${dep.type}] envs: ${dep.environments} scope: ${dep.scope} \nis registered more than once under the same environment or in the same scope',
	);