Improve template UX

Address UX in the Teklia bugzilla template form (#690).

This was originally a review, but after discussing with decoder, this is easy for us to change ourselves. Recording my feedback here so Teklia can work on more important improvements.

Currently, it looks like this (for "create"):

... or this (for "edit"):

In both cases, when the form is loaded it's unclear that you must choose a provider to get Product/Components populated. Could we auto-select the first provider? Loading one and having to change it is more obvious than having a blank field that unlocks the product/component selection.

I'd also rather have the "current" product and component be hidden fields, but with a "reset" button at the end of that line if the selection is changed from the original values.

The "reload" button is out-of-place under the "Product" heading. I think it should be included after the provider selection.

So here's my low-budget mock-up to summarize:

Start with the Teklia Bugzilla template form and compare its create and edit views with the screenshots in this issue. Verify the provider, product, component, current-value, reset, and reload interactions; done means the form follows the mock-up and makes provider-dependent selections clear.