🐛 Fixes codeSnip bug in YAML v3.

[jortel]

Fixes konveyor/tackle2-addon-analyzer#24

The issues seems to be a bug in yaml.v3. go-yaml/yaml#972

Also replaces:

if err != nil {
    h.Status(ctx, http.StatusBadRequest)
    return
}

with

if err != nil {
    err = &BadRequestError{err.Error()}
    _ = ctx.Error(err)
    return
}

so that the error is reported as BadRequest with an explaination of the error in the body instead of InternalServerError.

[mansam]

LGTM