Prevent windows from breaking workflow

### What Happened?

Currently, apps are allowed to disrupt user workflow:

i click on Steam
i do something else while steam figures itself out
suddenly the steam window appears at the top, interrupting me while it is drawing the updating steam thingy
i click somewhere else, go back to writing
suddenly the steam window appears at the top, interrupting me while it is drawing the main window
i click somewhere else, go back to writing
suddenly the steam window appears at the top, interrupting me with some news flash action spend money

Other apps can do this as well, but none as egregious and persistent so far
i remember OnlyOffice acting somewhat similarly.

### Steps to Reproduce

See above.

### Expected Behavior

Apps should not be allowed to force their presence to the user.
Should the user put their attention somewhere else, their current workflow and focus should be more important than app changes, and Gala should prevent applications from imposing their focus

we cannot realistically expect all apps to follow a sound design, nor to use the proper API - the DE should supersede over anything an application does, regardless of toolkit.
A similar issue is https://github.com/elementary/wingpanel-indicator-notifications/issues/285 discord not respecting proper standards and also breaking user workflow

### OS Version

8.x (Circe)

### Session Type

Secure Session (Wayland)

### Software Version

Latest release (I have run all updates)

### Log Output

```shell

```

### Hardware Info

_No response_