MINIFICPP-2751 Remove MinifiStatusToString before C Api is finalized

[martinzink]

Since these are well known static string literals we can omit this function from the C API, and let the consumers implement it if they require it.

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[szaszm]

I think this function is useful, and I'd consider reintroducing it later, but I can support removing it now, to minimize the initial API, and reduce the surface that we need to get right before 1.0.