Add missing mainstream status codes

[ghost]

The PR adds missing status codes for broader use.

To not pollute index.ts, status codes are published as a separate module hyper-ts/lib/Status and then merged into Status for backward compatibility.

[gcanti]

Thanks @matticala, what do you mean by "pollute"? I'd rather add them to the existing Status const.

[ghost]

@gcanti oh, nothing negative. It's just the status code list is big, I thought it might reduce the readability of index.ts.

[gcanti]

Thanks @matticala