Goal: Implement `PercentageParser<T extends string>`. According to the `/^(\+|\-)?(\d*)?(\%)?$/` regularity to match `T` and get three matches. The structure should be: `[plus or minus, number, unit]`. If it is not captured, the default is an empty string. For example: Source challenge: https://github.com/type-challenges/type-challenges/tree/main/questions/01978-medium-percentage-parser Reference explanation: https://github.com/ghaiklor/type-challenges-solutions/blob/main/en/medium-percentage-parser.md