netrw shouldn't be touching these in the first place.

fix #11089
ref #6892
ref #6695

(Credit: Zach Wegner, https://github.com/neovim/neovim/pull/11034)

Problem:    "precedes" in 'listchars' not used properly.
Solution:   Correctly handle the "precedes" char in list mode for long lines.
https://github.com/vim/vim/commit/bffba7f7042f6082e75b42484b15f66087b01941

Previously, the "precedes" character would be rendered on every row
when w_skipcol > 0 (i.e., when viewing a single line longer than the
entire screen), instead of just on the first row. Make sure to only
render it on the first row in this case.

Add a test for this behavior.

Fix documentation for the "precedes" character, which erroneously
stated that it was only active when wrap mode was off.

These options were previously global. A global-local window option
behaves closer to a global option "per default" (i e with :set),
but still supports local behavior via :setl

Also this restores back-compat for nvim_set_option("fcs", ...)
which are currently broken on 0.4.x but worked in earlier versions

Partial cherry-pick of b3686b1597ea202de464df72a88fb5c76fd1b814.

* test/functional/provider: display reason from missing_provider
* provider#node#Detect: skip / handle non-existing node executable

Vim patch 8.1.0856 (54d9ea6) caused a performance regression in Neovim,
when `set conceallevel=1 nocursorline` was used, since then due to
refactoring in 23c71d5 `w_last_cursorline` would never get updated
anymore.

Adds/uses `redrawdebug+=nodelta` for testing this.

Fixes https://github.com/neovim/neovim/issues/11100.
Closes https://github.com/neovim/neovim/pull/11101.