Some enhancements for hotkey commenting

[IS2511]

Environment（环境）

name	version
IDEA version	CL 2020.1.1
EmmyLua version	1.3.4.157-IDEA202
OS	Linux 5.6.0-2parrot1-amd64

What are the steps to reproduce this issue?（重现步骤？）

1. Write something on a line
2. (Optional) Write more than 1 line and select all of them
3. Press Ctrl + / or activate "Comment with Line Comment"

What happens?（出现什么问题？）

If there is no code selected, then the cursor jumps to the next line after commenting.
There are no spaces after --. Example:

local a = 10
a = 20

=>

--local a = 10
--a = 20

What were you expecting to happen?（期望？）

The cursor stays in the same position as before.
There is a space after every --.
Example:

local a = 10
a = 20

=>

-- local a = 10
-- a = 20

Any logs, error output, etc?（有没有什么log, error输出？）

Any other comments?（其它说明）

Also would be nice to add spaces for block comments ("Comment with Block Comment"). Example:

local a = 10
a = 20

Happens =>

--[[local a = 10
a = 20]]

Expected =>

--[[ local a = 10
a = 20 ]]

Of course the "uncomment" should remove these extra spaces in both line and block comments.

Feature request? Probably enhancement.