Qt/GameConfigWidget: Add Manual Texture Sampling

[SuperSamus]

Felt the need to add it due to #12059.

A few notes:

• The option in the GUI will be located under "Core", even though it is a "Video_Hacks"
• Didn't add a tooltip

[Pokechu22]

It looks like this now exceeds the line length limit and the linter wants it changed. This would probably the nicest-looking change:

  m_emulate_disc_speed->setToolTip(tr("Enable emulated disc speed. Disabling this can cause "
                                      "crashes and other problems in some games. "
                                      "(ON = Compatible, OFF = Unlocked)"));

(the linter itself doesn't like breaking up strings and makes a different suggestion.)

[SuperSamus]

clang-formatted it.

[MayImilae]

Screenshots please!

Regarding reversing disc speed, I don't really agree with Pokechu that reversing disc speed belongs in this PR. I'm not opposed to the change by any means, but IMO it should be in its own PR. But I suppose it doesn't matter, I certainly won't block this PR for that.

[Pokechu22]

Regarding reversing disc speed, I don't really agree with Pokechu that reversing disc speed belongs in this PR. I'm not opposed to the change by any means, but IMO it should be in its own PR. But I suppose it doesn't matter, I certainly won't block this PR for that.

To clarify, the disc speed button itself is already reversed; the option is labeled "emulate disc speed" but the setting itself is fastdiscspeed. The change I requested was to change the variable for the checkbox from m_enable_fast_disc to m_emulate_disc_speed so that the variable's name matches the check box's label, and thus the logic for the check box to the setting itself is clearer. This isn't a user-visible change (and if it were, then yes, it would be better for that to be in a separate PR).

[Pokechu22]

Tested and looks good to me.

[JosJuice]

This dialog really could use an overhaul to make the majority of settings available, but no reason not to merge this PR for now.