TextureConverterShaderGen: Set alpha to 1 on intensity formats if EFB lacks alpha

[Pokechu22]

We were already doing this for non-intensity formats, but it seems like the same applies to intensity formats. Note that the software renderer already sets alpha to 1 for both intensity and regular formats.

This appears to fix Rygar: The Battle of Argus's white screens, but I can't tell if this fix is actually correct (as the game's bloom effect doesn't seem to work properly still); I also haven't hardware tested this behavior (but it seems like it's probably correct to me). It seems to roughly match the results I was getting with the hardware FIFO player, though. The bloom effect works properly in areas where it is enabled (which does not include the area that was experiencing the white screen), and I've confirmed with the hardware FIFO player that I get matching results in areas with bloom enabled. I haven't done a standalone hardware test confirming this behavior, but it seems like it is almost certainly correct.

[Miksel12]

This also fixes https://bugs.dolphin-emu.org/issues/11875

[Pokechu22]

I've added a patch that fixes https://bugs.dolphin-emu.org/issues/12629 (a game bug in Pokémon Battle Revolution resulting in black appearing in some screen effects), since it's related to the offset issue (11875).

I've also done a writeup explaining both the offset issue and the patch I made: https://gist.github.com/Pokechu22/e9fa9037fe21312ff32475638b78ba27. I plan on doing a second writeup examining how the bloom effect works with Rygar: The Battle of Argus and why that effect didn't work in Dolphin. (Note that some additional testing has already shown that the bloom effect does work in some cases with this patch; the game tries to disable the bloom effect in other situations, including the one for the fifolog I was working with before, which is why I initially thought it was completely broken).

[Pokechu22]

And here's the writeup of Rygar's bloom effect: https://gist.github.com/Pokechu22/f9c6f22388f1c37570a546b80fdd7ddc

[dolphin-emu-bot]

FifoCI detected that this change impacts graphical rendering. Here are the behavior differences detected by the system:

• pbr-sfx on ogl-lin-mesa: diff
• pbr-sfx on ogl-lin-radeon: diff
• pbr-sfx on uberogl-lin-radeon: diff

_{^{automated-fifoci-reporter}}

[iwubcode]

Seems reasonable, untested.