Add search widget

[jphalip]

This widget is activated while doing a search (forward/backward, word search, etc.). It shows the current occurrence that you're on, as well as the total number of occurrences for the search terms. Works similarly to IntelliJ's built-in search tool.

This relies on search highlights being shown. But perhaps this is acceptable since the users who would care about this widget would also likely have highlights turned on?

If tests are expected for this, could you point me to some similar examples? I couldn't find tests, for example, for the macro widget.

[AlexPl292]

Related ticket: https://youtrack.jetbrains.com/issue/VIM-2544

[AlexPl292]

Hi, thank you for your interest, this is a nice feature. I've added a related ticket.
I think this PR needs the following updates, but let's discuss if you have a different opinion.

• Let's disable this widget if the shortmess option has a S flag. This will match the Vim behaviour: https://stackoverflow.com/a/60840571. However, this looks fine to have this widget enabled by default. This will also match the neovim default behavior.
• Relying on highlighting is not okay. We should properly count the number of occurrences and show them in the widget, as the widget and highlighting are two orthogonal features of the search.
  • In the same way, removing the widget inside the clearSearchHighlight is incorrect.
• Also, in Vim the widget is disabled on the new search (when / is pressed), or when the other mode is entered. This doesn't happen here.

[AlexPl292]

Directly accessing the content here leaks incapsulation. Let's have special functions like setSearch(current, total) and clearSearch().
(function names are subject to change).

[AlexPl292]

This is not a good place for running listeners. The finItOffset should be a clean function that returns the result of the search. If it's not clean, let's not make it worse at least.