feat: sided region selection

[IndianBoy42]

require'tsht'.nodes() can take {side = "start"|"end"}, similar to require'tsht'.move()

This reduces the hint labels to only that side, and when a hint is selected
instead of selecting the whole region, it selects from the current cursor to
the labeled key

I've definitely had use cases for it, like selecting/deleting/yanking/operating
on 'the rest' of the function, or argument list.

It's also a fairly small and non-intrusive change to the implementation. In
fact, while implementing this I was able to make a version of the move
function that doesn't depend on hop.nvim. Basically just make the
vim.cmd('normal! v') conditional. Is there any reason this wasn't done? I can
submit the PR too, if you want.