Core: Remove FPS, VPS and speed percentage from window title

[Simonx22]

Why?

• There's already an FPS widget that the user can enable.
• I don't think constantly updating values such as the FPS count should be in the title bar.

I can also further clean it up while I'm already touching this code. For example, I could remove the DSP section (which displays either HLE or LLE).
EDIT: This will be done separately in another PR in the future. I want to keep it simple.

Screenshots
Before:

After:

[MayImilae]

OBS doesn't care for our title bar shenanigans, so I'm sure everyone who wants to use Dolphin for streaming or recording will be quite happy with this change. I think this is a good move.

The DSP and other settings indicators are for support reasons, as it makes it easier to spot user settings in screenshots. That's less relevant than before due to Android and what not. It may be a good idea to make a "settings display" with our IMGUI HUD that the user can toggle on that just lists a ton of settings for us to inspect. Hmm, maybe we could do it in a fancy compact way, like a QR code or an interpretable string? That way it could show us ALL settings while still being compact? What do you think @Sam-Belliveau ? IMO the settings bits of the title bar shouldn't go until there's a replacement.

[Zopolis4]

Given that we have a obviously superior way of displaying the FPS and VPS information, this is a great change.

[MayImilae]

LGTM

[JMC47]

I'll be honest. I'm going to miss this as it's made seeing user's settings a lot easier. But I think this is a good, necessary choice regardless. It'll fix OBS freaking out, and we can come up with more solutions later.

[BhaaLseN]

This doesn't remove the settings (yet), only the FPS/VPS update. And the distinction between playing and movie playback I guess.

[JMC47]

Yeah, but this is definitely the start of that direction. Seeing FPS/VPS desyncs in the title bar was a thing back in the day too. Thankfully the imgui stuff now shows it too.

[Simonx22]

This PR is ready to review now. Build failures are not related to my changes.

[CasualPokePlayer]

There's already an FPS widget that the user can enable.

This actually is not suitable in one edge case: the Null backend, as there is no OSD with the Null backend. This means using the Null backend to judge how much a game is bottlenecked by the GPU is not really possible with this change.