Fix: Prevent Annotations errors from triggering a Preview failure

[pramodsum]

• Adds ability to emit silent preview errors without triggering the Preview error viewer. This is useful for cases such as annotations, where failures don't necessarily mean that the entire preview experience needs to fail

• Update tests

[boxcla]

Verified that @pramodsum has signed the CLA. Thanks for the pull request!

[jeremypress]

Why not just directly call this.emit('error', error) in the annotations error listener and not call triggerError?

[pramodsum]

preview.triggerError() generates a more thorough log event which i figured might be useful to also have.

    /**
     * Create a generic log Object.
     *
     * @private
     * @return {Object} Log details for viewer session and current file.
     */
    createLogEvent() {
        const file = this.file || {};
        const log = {
            timestamp: getISOTime(),
            file_id: getProp(file, 'id', ''),
            file_version_id: getProp(file, 'file_version.id', ''),
            content_type: getProp(this.viewer, 'options.viewer.NAME', ''),
            extension: file.extension || '',
            locale: getProp(this.location, 'locale', ''),
            rep_type: getProp(this.viewer, 'options.representation.representation', '').toLowerCase(),
            ...getClientLogDetails()
        };

        return log;
    }

[jeremypress]

This is what we do for silent preview errors in Preview.js

const err = new PreviewError(ERROR_CODE.INVALID_CACHE_ATTEMPT, message, { file });
this.emitPreviewError(err);