[2.8] Summarize the multibytes body stream comfortable

[TheNorthMemory]

solved #588

[stale]

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[GrahamCampbell]

I'm not sure I like this approach, as it assumes UTF-8 encoding. If we are to make that assumption, this implementation seems over-complex. Would it not be simpler to fetch 4x the bytes and then use mb_substr?

[TheNorthMemory]

yes, indeed, using mb_substr is better than manual detection. I saw that comment #561 as for few dependencies reason so it's leave the ext-mb alone. If this package should be required the ext-mb, I've happy to see using the sample way patch the Malformed UTF-8 characters issues.