grpc: Add support for max frame length in gPRC frame decoding

[tyxia]

The workflow:

• Client of gRPC decoder configure the max_frame_length via setMaxFrameLength()
• At beginning of gRPC frame decoding process ( before frameDataStart()), total length of the frame is determined.
• If max_frame_length is configured and total length exceeds the limit, the decoding process which includes excessive data addition/storage (i.e. frameData()) will be skipped and returned.

The use case/ motivation: Enable max_receive_message_length in Envoy-gRPC (which use gRPC decoder) .

• When the message is over limit, it can be rejected before frame data is fully decoded (i.e. expanded).
• This can prevent malicious attack , for example, unbounded and huge message is sent over channel and is injected and buffered in Envoy over Envoy-gRPC.

Next step:

• Refactor bool Decoder::decode method: Change the return type from bool to absl:status so that the caller can identify whether it is decoding error or over-limit error.

[repokitteh-read-only[bot]]

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:cat:

Caused by: https://github.com/envoyproxy/envoy/pull/32511 was opened by tyxia.

see: more, trace.

[tyxia]

/assign @htuch

PTAL, Thanks!

[tyxia]

/assign @yanavlasov

Add Yan per offline discussion