http: support validation options when creating a file through JSON

[vxio]

ACH Version: v1.9.2

What were you trying to do?
Create an ACH file from JSON through the HTTP server with validation options set.

What did you expect to see?
A successful request given the validation options.

[vxio]

We should be able to enable this by calling SetValidation in this block:

ach/server/files.go

Lines 171 to 176 in 0230442

	// Read body as ACH file in JSON
	f, err := ach.FileFromJSON(bs)
	if f != nil {
	req.File = f
	}
	req.parseError = err