Performance improvement: `IReadOnlyList<string> TranslationNames` -> `IReadOnlySet<string> TranslationNames`

[adambajguz]

Feature description

TranslationNames property is currently impleemented as a read only list of strings. I think it would be better to change it to a read only set (IReadOnlySet<string>) because it allows for a faster checks like Contains, which in my opinion are more important in this context than index-based access to translations.

[bartoszlenar]

Thank you, @adambajguz , for your input. You might be right and although this isn't part of the project that will be under constant pressure, I appreciate that this change is 100% about performance.

I've verified that it could be done relatively straightforward, but I'd need more time to think about possible complications. One of them, naturally, is a version bump to 3.0.0 and that's why this issue will probably wait while along with other breaking changes (to reduce chaos).

[bartoszlenar]

Hi @adambajguz

Since IReadOnlySet isn't a part of .NET Standard 2.0 Validot is now basing on, I'm scheduling this in 2023, as a part of the big update that will change the base to the newest .NET versions.