Increasing Swoole's package_max_length

[Nick-S-2018]

Proposal:

We may need to increase the default value of package_max_length in Swoole. That would help to accelerate dumps made with Elasticdump, since now we have to limit dump batch size to match this value.

Checklist:

^{To be completed by the assignee. Check off tasks that have been completed or are not applicable.}

• Implementation completed
• Tests developed
• Documentation updated
• Documentation reviewed
• Changelog updated
• OpenAPI YAML updated and issue created to rebuild clients

[Nick-S-2018]

@donhardman, pls check if this can be done and if such change doesn't cause any side effects in Buddy,

[donhardman]

Please take a look here #427

I tried to run some benchmarks and the new parameters do not affect it, so if it's enough, feel free to merge. If we need to increase more, let me know.