Add insert_space command

[yerlaser]

Add command to insert whitespace.
Motivation: I would like to add a special binding in normal mode to Shift-Space shortcut.
However, in insert mode it is very easy to hit this combination by accident as Shift often remains depressed after a previous character was inserted.
Therefore, I would like to assign Shift-Space to insert space, just like Space does, but only in insert mode.

[sicher]

Shouldn't you already get space with shift-space in helix (and everywhere else) by default? I do.

[yerlaser]

Shouldn't you already get space with shift-space in helix (and everywhere else) by default? I do.

Yes, that's because your terminal is configured by default to send space character when you press Shift-Space.
But, you can change it.

[the-mikedavis]

See #2116

[yerlaser]

See #2116

Thanks, that's another use case that I didn't think of.
In general, though, this command can have a few other uses.

In that other PR you refer to the Macro Style Bindings, but that feature seems to be stalled since 2021.
May I suggest to have this now and once that arrives all three insert commands can be replaced by one.

[tmke8]

This could also be generalized to an :insert-text typeable command, and then you'd use

"S-ret" = ":insert-text ' '"

There is an open issue for that: #2797

[yerlaser]

OK. I see.