Converts some notify_ghosts args to bitflags, multilines all notify_ghosts calls (#79320)

## About The Pull Request

This helps clean up my favorite helper proc in the whole codebase,
`notify_ghosts()`.

The notify_suiciders, ignore_mapload, and flashwindow args are GONE.
They have been replaced with the notify_flags bitflag argument. This was
intended to make deadchat announcements a bitflag argument too, but
those got reverted right before I originally wanted to submit this PR.

The on-screen popup now shows the notification body when you hover it
with your mouse again. The format is now `[notify_ghosts message] --
[click action (orbit/jump/play)]`

Every single `notify_ghosts()` call has been changed to multiline format
and has been given trailing commas. Pretty!
## Why It's Good For The Game

Cleans up a proc that is very popular and going through a lot of changes
at the time.

Allows for further flexibility when this proc inevitably gets tweaked or
improved. 12 -> 10 args is an improvement, and it doesn't impact the
helper's flexibility at all.
## Changelog
🆑 Rhials
code: The notify_ghosts proc has been cleaned up. Please report any
abnormal changes in deadchat notification behavior.
qol: The on-screen deadchat popups now contain the notification blurb
when hovered with your mouse again.
/🆑

code/game/objects/structures/spirit_board.dm

@@ -56,7 +56,11 @@
 
 	if(virgin)
 		virgin = FALSE
-		notify_ghosts("Someone has begun playing with \a [src] in [get_area(src)]!", source = src, header = "Spirit board")
+		notify_ghosts(
+			"Someone has begun playing with \a [src] in [get_area(src)]!",
+			source = src,
+			header = "Spirit board",
+		)
 
 	var/new_planchette = tgui_input_list(ghost, "Choose the letter.", "Seance!", ghosty_options)
 	if(isnull(new_planchette))