Handle string-typed Time Fields #10
Description
A community zync user attempted to use the plugin and happened to have a string-typed field that held a timestamp value and was stumped when the plugin wasn't able to plot data just by specifying it as the Time Field. While won't be as efficient to do the conversions on the fly at the JavaScript layer, it would surely be user friendly if the plugin could somehow handle this case automatically (and perhaps issue a warning to the user so they know they're not seeing ideal performance.)
For now, a change in #14 has made it such that the plugin does detect when the user has picked a non-time field and surfaces an error message advising them as to why it's not working.