Doesn't seem to have support for Flags Enums

My team really likes this project and would like to use it for our codebase! Unfortunately, we have several flags enums and they don't seem to be compatible with this project. :(

The `FromValue` method throws a SmartEnumNotFoundException when given a flags enum value as well as casting a flags value.
```
// Given SomeEnum.A is 1 and SomeEnum.B is 2, all three throw the exception
SomeEnum.FromValue(SomeEnum.A | SomeEnum.B);
SomeEnum.FromValue(3);
(SomeEnum)3
```
Also, there's no way to get the Name of multiple values with the logical OR operator like we get when the `Flags` attribute is placed on an enum (i.e. `SomeEnum.B | SomeEnum.C` => `B, C`).

Will this project include this support in the near future?

Start at the FromValue entry point and the SmartEnumNotFoundException path, reproducing the three combined flag-value examples from the issue. Define and verify behavior for logical-OR values and names matching the Flags attribute’s B, C example; done means supported combined values no longer throw and their names are returned as specified.

Written by the indexing model from the issue text.