fix(actions.qflist): make it work with vim quickfix commands

[cgsheeh]

Changes functions that use setqflist in r mode to instead use
mode. This makes the Telescope quickfix list action send results
to a new list in the quickfix stack instead of overwriting the
entries in the current list. Doing so enables :chistory, :colder
and :cnewer functions to review results of previous Telescope
queries.

The location list uses a similar API and is updated in this PR also
(ie this also enables :lhistory, :lolder and :lnewer).

[kkharji]

🤔 hmmm I get how practical it is to have new items added to an existing list. But I have a feeling that maybe it should rather be a global option or new function. The thing is many users of telescope expect the behavior of having new quickfix list on send_to_quickfix, like me.

Since it's vim default behavior, then it should be the default here, however, with an way for current users to opt-out this change.

Otherwise, LGTM. btw great argument #1739

[cgsheeh]

The thing is many users of telescope expect the behavior of having new quickfix list on send_to_quickfix, like me.

@tami5 Just to clarify, after this change you will still see a new quickfix list on send_to_quickfix. The difference is the previous quickfix list will now be in the quickfix list stack, recoverable with :colder after you send another Telescope query to the quickfix list (and the same change is true of the location list). The current behaviour of send_to_quickfix is to remove all the existing entries in the current quickfix list and replace them with the new entries. You can already use add_selected_to_qflist to append to the current quickfix list (with <M-Q> IIRC). See :h setqflist, the section on actions. Confusingly the ' ' action is in a paragraph at the end instead of formatted similarly to the r and a actions (which is perhaps a bug in and of itself).

Apologies in advance if you already understood all this, just want to make sure we're on the same page. If you could pull down the PR and give it a try I'd greatly appreciate it!

[kkharji]

Oh I see, I totally misunderstood it as feature rather than a bug. I did some testing and indeed no big behavior changes to what the user would expected. but rather an access to a new suite of quickfix driven workflows.

Thanks for the clarification @cgsheeh