2A03 pulse volume 1 is silent

[pinobatch]

Describe the bug
2A03 pulse volume 1 is played as silence.

To Reproduce
Steps to reproduce the behavior:

1. On Xubuntu 23.10, build FCEUX from source code
2. Download All_pulse_volumes.zip, extract the NSF, and play it
3. Hear a series of dits and then a tone, several times
4. Hear no tone after 1 dit

Expected behavior
After 8 dits, a tone is played at volume 8. After 7 dits, volume 7. After 1 dit, volume 1. Mesen, NSFPlay, and PowerPak behave this way.

Screenshots
I'd provide the NSFPlay render, but I don't know if GitHub Issues supports any free audio file formats.

(please complete the following information):

• OS and Version: Xubuntu 23.10 x86-64
• Version of FCEUX used: 5495c7e Qt

[negativeExponent]

volume adjustments for sound channels needs "adjusting" since it can cause final volume to be zero. in this test case, pulse channel at 1 tick has value fo 1. based on this channel computation:
(pulse vol * modifier) / 256
will turn a pulse volume at '1' with a modifier of 255(max volume in audio settings) will result in 0, turning off that channel.

there is a case where a modifier value of 256 will skip these volume adjustments but that doesnt seem to be accesible through fceux' audio settings.

@zeromus @thor2016

[zeromus]

problem only on QT port (ConsoleSoundConf.cpp, around lines 175..)