Iterate more aggressive string truncation if needed

[waltjones]

Fixes #864

Current truncation strategy:

1. Limit the number if stack frames
2. Truncate all strings to 1024, then 512, then 256 bytes.
3. Limit to only the most current stack frame.

This PR extends string truncation to 128 and 64 bytes, and adds the size of all truncation attempts to the error message when truncation fails.

It has been suggested that parts of the payload can be removed entirely as a truncation step. This may be appropriate, but we don't know yet which part is causing the issue or the nature of why it's oversized.