chore(refacto): move parent and sibling functions into actions

BREAKING CHANGE:
- move parent_node and sibling functions from lib to
  actions/movements.lua.

lua/nvim-tree/actions/movements.lua

@@ -0,0 +1,104 @@
+local utils = require'nvim-tree.utils'
+local view = require'nvim-tree.view'
+local diagnostics = require'nvim-tree.diagnostics'
+local lib = function() return require'nvim-tree.lib' end
+
+local M = {}
+
+local function get_line_from_node(node, find_parent)
+  local node_path = node.absolute_path
+
+  if find_parent then
+    node_path = node.absolute_path:match("(.*)"..utils.path_separator)
+  end
+
+  local line = 2
+  local function iter(entries, recursive)
+    for _, entry in ipairs(entries) do
+      local n = lib().get_last_group_node(entry)
+      if node_path == n.absolute_path then
+        return line, entry
+      end
+
+      line = line + 1
+      if entry.open == true and recursive then
+        local _, child = iter(entry.entries, recursive)
+        if child ~= nil then return line, child end
+      end
+    end
+  end
+  return iter
+end
+
+
+function M.parent_node(node, should_close)
+  if node.name == '..' then return end
+
+  should_close = should_close or false
+  local altered_tree = false
+
+  local iter = get_line_from_node(node, true)
+  if node.open == true and should_close then
+    node.open = false
+    altered_tree = true
+  else
+    local line, parent = iter(lib().Tree.entries, true)
+    if parent == nil then
+      line = 1
+    elseif should_close then
+      parent.open = false
+      altered_tree = true
+    end
+    line = view.View.hide_root_folder and line - 1 or line
+    view.set_cursor({line, 0})
+  end
+
+  if altered_tree then
+    diagnostics.update()
+    lib().redraw()
+  end
+end
+
+function M.sibling(direction)
+  return function(node)
+    if node.name == '..' or not direction then return end
+
+    local iter = get_line_from_node(node, true)
+    local node_path = node.absolute_path
+
+    local line = 0
+    local parent, _
+
+    -- Check if current node is already at root entries
+    for index, entry in ipairs(lib().Tree.entries) do
+    if node_path == entry.absolute_path then
+      line = index
+    end
+    end
+
+    if line > 0 then
+    parent = lib().Tree
+  else
+    _, parent = iter(lib().Tree.entries, true)
+    if parent ~= nil and #parent.entries > 1 then
+      line, _ = get_line_from_node(node)(parent.entries)
+    end
+
+    -- Ignore parent line count
+    line = line - 1
+    end
+
+    local index = line + direction
+    if index < 1 then
+    index = 1
+  elseif index > #parent.entries then
+    index = #parent.entries
+    end
+    local target_node = parent.entries[index]
+
+    line, _ = get_line_from_node(target_node)(lib().Tree.entries, true)
+    view.set_cursor({line, 0})
+  end
+end
+
+return M