Forbid large-size-value writes to Pegasus

[neverchanje]

Feature Request

Is your feature request related to a problem? Please describe:

large-size-value writes will lead to the instability of Pegasus. We encounter many cases where the client continuously wrote >=1MB value (though in quite low qps) which caused high tail latency of other tables, even caused the program somehow coredump.

Describe the feature you'd like:

Support a configuration (like 'max_allowed_write_size') to limit write size. If the value is larger than 1MB, pegasus server replies with ERR_INVALID_ARGUMENT or other suitable error code.

The better measure is that we can also add limit on java client to avoid invalid request.
related issue XiaoMi/pegasus-java-client#94

Describe alternatives you've considered:

Teachability, Documentation, Adoption, Migration Strategy: