feat(linewise-textobjs): add count and iteration support

[TheSast]

It should be noted this does not yet add support for the direction in which iteration goes, thus, right now it always goes down-wards for non-block textobjs.
I'll normalize variable names and update documentation later on.
I've already been running these changes daily for more than a month, slowly ironing out any issues I found, but I figured it would be important to set up a draft pr for the purpose of discussion, especially around the indentation textobjs.

Checklist

• Used only camelCase variable names.
• If functionality is added or modified, also made respective changes to the
  README.md (the .txt file is auto-generated and does not need to be modified).

[chrisgrieser]

Thanks for the effort, but tbh, I am not entirely sure if I want this merged.

Iteration/counts are a relatively niche feature most people won't use. Instead, I (and probably most people) simply go to a line with the desired indentation level before using ii/ai, which gives the same result, but in a simpler way.

Thus, it's my impression that this PR falls into the category of "increase complexity significantly for a niche use case for a minority of users," something I generally learned to avoid when maintaining OSS projects.

[TheSast]

I understand where you are coming from.
Since I was already planning to add count support to the charwise textobjs, as I find their lack of count support a dealbreaker, what would you suggest me to do? should I fork this project directly or set up a new plugin containing only the subset of textobjs I use and consequently can properly maintain?

[chrisgrieser]

Depends, really. There are various options:

• You make an "extension" for various-textobjects, which hooks into the plugin and modifies the behavior, making this plugin basically a dependency of yours
• you create a fork / separate plugin
• in case the changes to add count support are not that big, and you can explain to me why it's a dealbreaker there (I honestly have no idea, since I don't use counts normally), we could also consider merging them here

Depends a bit on your preference and the concrete situation