[php-src] Issue #9352: Retrieving an enum case by its name

Issue: https://github.com/php/php-src/issues/9352 Author: ollieread ### Description I'm proposing that we add two new methods to the UnitEnum interface, named and tryNamed, which exist as the counterparts for BackedEnum::from and BackeEnum::tryFrom, but use the enum name. I believe this would allow developers to avoid arbitrarily creating backed enums where the name will do, without writing unnecessary userland code to retrieve a case given its name. ## Reasoning We currently have the from and tryFrom methods for retrieving backed enums based on their values, but we have no way to retrieve an enum case using its name. There are two possible ways to solve this in userland. The first is to make the enum backed, but that can introduce unnecessary code. Take the following Status enum. ```php enum Status: string { case Todo = 'todo'; case InProgress = 'inprogress'; case InReview = 'inreview'; case Done = 'done'; } ``` While not super complex, the string value is entirely unnecessary, as it's just a lowercase version of the name. The second solution is to store $enum->name and then retrieve the case by doing something like the following: ```php foreach (Status::cases() as $case) { if ($case->name === $name) { return $case; } } ``` There is probably a more efficient way of doing this, but I think this accurately portrays what I mean. While not hugely complex, each of these solutions requires the writing of unnecessary code for something that should be easily achieved.