Simplify approach to providing an alternative fzf file find invocation

[sidkshatriya]

• Revert some changes. Create a new str option fzf_file_alternative_command.
• Also provide a shortcut 'o' by default

Here is the sample kakrc configuration now using the simplified approach.

hook global ModuleLoaded fzf-file %{
    set global fzf_file_command "rg -L --files"
    set global fzf_file_alternative_command "rg -L --files --no-ignore"
}

---

P.S. As this commit reverts some changes of the previous commit cb07538a88dd51b1c03800d6c451d2d71e7b80a5 , it is also useful to see the following.

https://github.com/andreyorst/fzf.kak/compare/95b12b1fe93c6db0441c61062823231a28eed037..a1012402af3db8411144877437697fb678424a24

The above link compares this PR with the commit

commit 95b12b1fe93c6db0441c61062823231a28eed037
Author: Andrey Listopadov <andreyorst@gmail.com>
Date:   Wed Mar 23 19:55:27 2022 +0300

    fzf-grep file preview

The above diff is probably simpler to review.

[andreyorst]

hm, so instead of passing additional arguments to fzf-file this PR makes a separate command for that purpose? I think your previous method is more simple in a sense that it's just additional arguments, taht allow you to define your own versions of fzf-file and binding them to convenient keys, like "only search hidden files" or "only search current buffer's extension files". This one seems less flexible in this regard.

[sidkshatriya]

Here is my reasoning why this is a better approach:

• This method is simpler for the user. They don't need to define an explicit shortcut. Here the 'o' key is explicitly linked to the alternate command
• You may want to use "rg" as the tool normally but "ag" as the alternate tool. This approach will allow that
• Sometimes you are not able to undo the effect of a previous switch. Supposing your normal command has some switch --abc. But now you need --xyz. Also it may be that --abc and --xyz may be mutually exclusive -- you won't be able to specify --xyz if --abc is already there. However this simpler approach will allow that.

In general this approach allows an arbitrary alternative command and it's simpler for the end user...

[andreyorst]

Maybe we could have both ways, as they aren't mutually exclusive?