Save All Scenes shortcut frequently does not work

### Tested versions

Found in v4.5.stable.official [876b29033], not present in 4.4 official. I consider this a UX side regression.

### System information

Godot v4.5.stable - Windows 10 (build 19045) - Single-window, 1 monitor - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 2070 SUPER (NVIDIA; 32.0.15.7688) - Intel(R) Core(TM) i9-9900KF CPU @ 3.60GHz (16 threads) - 31.92 GiB memory

### Issue description

There are a number of primary symptoms in the 4.5 update affecting saving within the editor. Most of these stem to a change to the "save all scenes" shortcut.

1. Always: Shortcuts relating to saving scenes, including "save scene" and "save all scenes" will not trigger.
2. Rarely: The (*) in the window title will persist even after all scripts and scenes have been saved. Cause unknown.
3. Possibly: Many saving operations no longer cause a progress bar to appear. There is no feedback to whether or not a save has occurred.

I want to focus this issue on point number 1, as it is the root cause in why the editor feels different now. And it's preventing me from assessing if 2 and 3 are *actually* different now, or if its just a symptom of 1.

**Apparent behavior in 4.5**

* The "save all scenes" shortcut now requires the editor to be in a "scene editing" state to be able to trigger.
* This requires focusing the Scene dock, or interacting with a Scene in the Main view.
* This shortcut **sometimes does not work** even when the Main view is displaying a 2D/3D editor.
* It appears to only save scenes now. (Perhaps, due to it not saving all resources anymore, that is why the (*) is not clearing?)

**Apparent behavior in 4.4**

* The "save all scenes" shortcut would execute regardless of the open view.
* It would execute regardless of if any scenes actually need saving. Defined by the saving progress bar popup appearing for a split second, even when nothing was saved.
* It would function in conjunction with the script editor. Saving all open scripts, and saving all open scenes, and saving all edited resources in the inspector history.

**Attempted Remedies**
* Rebinding "save all scenes" to ctrl+s from its default (I have done this in every Godot version). This does not affect the behavior.
* Removing conflicting shortcuts, so that only this one shortcut is triggered by ctrl+s. This does not affect the behavior.

**Proposed fix**
Either, once again make she shortcut independent of the current editor focus.
Or, allow setting shortcuts as "global" so individual shortcuts can ignore the editor focus.
Or, add a "save absolutely everything everywhere" shortcut! :D

### Steps to reproduce

1. Edit a scene
2. Move to the script editor
3. Use the "save all scenes" shortcut (not from the menu, but actually hit the shortcut)
4. Nothing happens | Previous this would save all scripts, scenes, and resources.

### Minimal reproduction project (MRP)

-

No files or tests are named. Reproduce the issue by editing a scene, switching to the script editor, and invoking the Save All Scenes shortcut; then trace the Godot editor's shortcut handling and save-all entry point. Done means the shortcut works regardless of editor focus and saves the expected open scenes, scripts, and resources.

Written by the indexing model from the issue text.