fix: Make NERDTreeFind to handle directory case sensitivity (preservim#1387)

Co-authored-by: Dan Gibson <[email protected]>

Author: rzvxa

lib/nerdtree/path.vim

@@ -549,7 +549,7 @@ function! s:Path.isUnder(parent)
         return 0
     endif
     for i in range(0, l:that_count-1)
-        if self.pathSegments[i] !=# a:parent.pathSegments[i]
+        if !nerdtree#pathEquals(self.pathSegments[i], a:parent.pathSegments[i])
             return 0
         endif
     endfor

lib/nerdtree/tree_dir_node.vim

@@ -121,8 +121,14 @@ function! s:TreeDirNode.findNode(path)
     if a:path.equals(self.path)
         return self
     endif
-    if stridx(a:path.str(), self.path.str(), 0) ==# -1
-        return {}
+    if nerdtree#caseSensitiveFS()
+        if stridx(a:path.str(), self.path.str(), 0) ==# -1
+            return {}
+        endif
+    else
+        if stridx(tolower(a:path.str()), tolower(self.path.str()), 0) ==# -1
+            return {}
+        endif
     endif
 
     if self.path.isDirectory