Make the "Hide Lines" hidden/unhidden state toggable

[victorel-petrovich]

Description of the Issue

The Hide Lines feature (shortcut Alt+H, located in: Menu > View > Hide Lines )
would be a much more useful feature if you could toggle the symbols/markers to show/hide the lines, as it's possible for folded lines.

Wanted by others too:
https://community.notepad-plus-plus.org/topic/16203/remember-hidden-lines-after-unhiding

Steps to Reproduce the Issue

1. Select some lines and hide them
2. Click on other lines, then click on the triangle symbols to unhide the lines

Expected Behavior

To still see the markers, so that could hide/unhide the lines again if needed.
Also, preferably, to see a vertical line in the margin, indicating which lines belong to the hiding-group.

Actual Behavior

The symbols disappear. You have to reselect to hide again...

Debug Information

Notepad++ v8.5.4 (32-bit)
Build time : Jun 17 2023 - 20:40:14
Path : C:\Users\Vic\AppData\npp.8.5.4.portable\notepad++.exe
Command Line :
Admin mode : OFF
Local Conf mode : ON
Cloud Config : OFF
OS Name : Windows 7 Ultimate (32-bit)
OS Build : 7601.24546
Current ANSI codepage : 1252
Plugins :
mimeTools (2.9)
NppConverter (4.5)
NppExec (0.8.4)
NppExport (0.4)
PythonScript (2)