Closes #45603 

I wanted to open this and start a conversation/get some feedback after
encouragement from people in the above discussion. Currently, the
enabled `show_menus` setting causes them to open when hovered over,
which generally breaks with a longstanding user expectation for desktop
applications. It could be argued that this behavior shouldn't exist at
all, but it's of course possible that some people prefer it. To that
point, I explored adding an additional option, `show_menus_on_hover`,
which is disabled by default.

This also checks as to whether any menu is in use so that clicking a
menu and then navigating through them opens them accordingly. As
mentioned in the discussion, this doesn't address an existing bug where
some of the pane icons will blink while moving through the menus.

I'm unsure of how this specifically can or should be tested since I'm
learning as I go, so for now there's just screenshots from the
aforementioned discussion. I'm open to suggestions. As I'm sure some
might guess, these changes don't really apply to macOS as the menus are
always visible. I also do not have access to a Windows installation at
this point.

(Tested in Arch Linux / KDE Plasma 6.5.5; ran the release build to take
clips)


![hover-on](https://github.com/user-attachments/assets/6601f927-ef68-4d24-b05b-c442ecc87137)

![hover-off](https://github.com/user-attachments/assets/716e79e2-5a84-41df-a394-acfbac59b2be)
<img width="1380" height="752" alt="setting"
src="https://github.com/user-attachments/assets/7a3614ae-d5fd-4767-9ca4-330c91e40bcc"
/>

Release Notes:

- Changed title-bar menus to require a click before opening. Enable
`title_bar.open_menus_on_hover` to open them on hover instead.

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Co-authored-by: Smit Barmase <heysmitbarmase@gmail.com>