Add string for space key

It always looked a bit odd in the input manager when the space bar was assigned somewhere.
Add keybinding helptext to more menus

This commit adds a short help text for these menus to show the correct key to open the keybindings menu:
* Construction menu
* New character (first tab only)
* Overmap
Slightly more reasonable default keybindings

NEXT_TAB in character creation can no longer be done with TAB, because this is already used by gender,
so you could get stuck in the profession tab by switching tabs with TAB, which may be confusing.

Random names (character and world) are now using “*” instead of “?” to allow the keybinding menu to appear on “?”.
Show actual keybindings in world manager name tab
Cosmetic edit to default keybinding file

“SPACE” instead of “ ”, simply to be more consistent
Let the mod manager show the actual keybindings
Reserve world names “TUTORIAL” and “DEFENSE”
Use different font color for special saves

In this case, “TUTORIAL” and “DEFENSE”.
refactored season length calculation for consistency
Overmap signs
JSON signs
World Factory signs
Mod manager signs
Mondeath signs
Kill vines fix
A few capitalization fixes.
M2010 fix.

Fixes https://github.com/CleverRaven/Cataclysm-DDA/issues/8538.
Player signs
Function build update
Merge to mainline