Fix 'dropping for storing' style

[nditada]

The current design looks like this:

The original design was this:

Let's discuss what we want to do. Is there any reason why we don't want to apply the original design? At least the "store" seems more clear to me than "new value". cc @jkicillof @bcardiff

[bcardiff]

I don't recall if we differ intentionally wrt original design.

The store would appear always, as soon as the drag started or upon hover?

States:

• There is no interaction with the table, so the placeholder for a new record is shown.
• There is a insert record action, so some columns have pills for the specified values. Right now we show 'new value' on these
• There is a filter action, so some columns have pills for the filtered values. Right now we show a placeholder pill for values in other columns. Upon dropping over these pills we are able to update the fields. Yet there is not feed back that this will happen.

[bcardiff]

IRL dump with @jkicillof

• description text (ie: store/filter) and solid line should appear only on hover
• every place where you can drop should have dashed pill. currently missing the table headers.
• dashed should be more dot-like line

[asterite]

It's still not clear what needs to be done here. Should "new value" or "store" be used? In any case, if we use "new value" or "store", the text shouldn't change when dragging over a field because its width will change and that's a bit confusing/disturbing. I think "new value" is somewhat clear: it's a placeholder for a new value, while the actions on the left would say its storing this new value.

[jkicillof]

Maybe we should replace "store" with "update" to make it clear. When the user creates a new row we use "New value", when the user updates an existing row we use "update". The dropping area width should be fixed, if the text doesn't fit we should use ellipsis.