support copy/paste on the parameters page

[pavoljuhas]

<Ctrl-C> on the Parameters page copies the entire Fit. There is no way to copy or paste the values in the parameters grid.

[sbillinge]

I think we want a context-sensitive right click behavior here maybe? @pavoljuhas , pls can you write a slightly more complete UC for the behavior you want as a first step, and then if @chiahaoliu needs help where to dive into the code for that, help with that, but perhaps the UC is enough.

[pavoljuhas]

Sure - here is one UC. I have a series of temperature dependent fits, with the same structure model and a same group of parameters. I have refined fit-1 and would like to start fit-2 from its refined values. A want to select the "Refined" column at the fit-1 --> Parameters panel, press Ctrl-C/⌘C, to copy its values, then go to fit-2 --> Parameters page, click on the first value of the Initial column and press Ctrl-V/⌘V to paste. The Copy/Paste functions should be also available from the context (right-click) menu.

If possible, Copy/Paste should also work for the "Fixed" column to copy the same set of yes/no flags, but the Paste function then needs to ensure the flags get written only to the "Fixed" column in the target Parameters grid. (User does not want all zeros and ones in the Initial column).