Motivation:
HPACK static table is organized in a way that fields with the same
name are sequential. Which means when doing sequential scan we can
short-circuit scan on name mismatch.
Modifications:
* `HpackStaticTable.getIndexIndensitive` returns -1 on name mismatch
rather than keep scanning.
* `HpackStaticTable` statically defined max position in the array
where name duplication is possible (after the given index there's
no need to check for other fields with the same name)
* Benchmark for different lookup patterns
Result:
Better HPACK static table lookup performance.
Co-authored-by: Norman Maurer <norman_maurer@apple.com>