Review use of `Error::io()` to find cases where that error should be a different type

[wjones127]

Early in the codebase, we were sloppy about error types. Many errors were just defaulted to using IO errors, even if they had nothing to do with IO failures.

#3159 is an example of this, but there are many more obvious ones throughout the codebase.

We need to review these instances and map them to a more appropriate error type. Pay special attention to ones that need to be changed to Error::InvalidInput.

[lichuang]

i will have a try