/kind improvement
Before this, while retrieving data (query/search), we first copy the
data into a fixed vector, and then copy data from this into the proto
field.
Now we can directly copy the data into the proto field.
This optimization can't be done with int8, int16 due to the proto
doesn't provide the two types, we store them in int32s
Also, this can't be done with variable length field like string, JSON,
see https://github.com/protocolbuffers/protobuf/issues/10866. I tried
but it seems proto doesn't guarantee the memory layout as we expected,
it crashed
pr: #28106
Signed-off-by: yah01 <yah2er0ne@outlook.com>
