Adjust JSON limit to 2MB and report on sizes

[peter-formlogic]

PR Type

Other

PR Checklist

• Tests for the changes have been added / updated.
• Documentation comments have been added / updated.
• A changelog entry has been made for the appropriate packages.
• Format code with the latest stable rustfmt.
• (Team) Label with affected crates and semver status.

Overview

This adjusts the default limit of JSON payloads to 2mb from 32kb and adjusts the error to include what the limits are when they're hit. As this changes the error enum & has possibly knock on effects to memory usage by allowing more through this is probably considered a breaking change.

To justify the increase, I have looked at other defaults in other software for what their limits are:

• in .Net it's set to 2097152 (which they say is 4mb? not sure why)
• In Tomcat the max post size is set to 2mb
• In PHP the default upload size is 2mb

(Honestly, I'd much prefer having no limit at all by default as these things seem to have a way of coming back to bite at unrealistic times, like 2am on a saturday morning!)

[fakeshadow]

I think it's fine to relax the limit in general. We need a changelog for limit and error changes

[peter-formlogic]

Done!

[thalesfragoso]

Thanks for the PR, is this just waiting for the conflicts to be resolved ?

[peter-formlogic]

@thalesfragoso sorry didn't notice that it was blocked on conflicts. I've merged master into this PR