Even tough the sound visualizer has `channels` as one of its parameters
it wasn't using it properly.
### Problem description
The biggest problem is that at each frame the index was being advanced
per channel frame_count increments. The number of channels also
determines how many graph will be needed to display the graphs of the
visualized sound files. Besides these two problems there were many
others like incorrect playback time, cracking audio, etc. which will not
be mentioned.
### Implementation description
To sample the signal a channel sampler was created based on the one used
previously that returns as many sampled signals as there are channels.
This PR aims hopefully at fixing all the problems encountered, and it
has been tested extensively using `Audacity` exported samples to ensure
the visualizer fidelity on playback and graph appearance.
### Screenshots
### Problem description
#### Problem 1
In borderless mode ImHex disables the standard macOS titlebar rendering
and input processing. As a result double clicking the titlebar does not
trigger the native macOS behavior set in `System Settings -> Desktop &
Dock -> Double-click a window's title bar to [Zoom/Minimize/Do
nothing]`.
#### Problem 2
The ImHex window shows up as blank/transparent when de-minimizing it
from the dock.
#### Problem 3
Widgets experience ghost hover inputs from the past position of the
cursor during live resizing.
### Implementation description
ImGui elements consume input events in the order they are drawn. As a
result by "drawing" an `InvisibleButton` over the content area of the
titlebar we can catch unprocessed clicks in the titlebar area.
Connecting this button's double clicks to the native window is then a
trivial endeavour.
The blank windows was caused by the rendering stack clearing the GL
buffer, but proceeding to draw nothing in it. I have short circuited
this path.
Ghost hover inputs were squelched by consistently moving the ImGui
cursor to `0, 0` during a live resize. The OS will dispatch a cursor
positioning event once the resizing ends, restoring normal behavior.
### Screenshots
N/A
### Additional things
N/A
---------
Co-authored-by: Nik <werwolv98@gmail.com>
This PR adds a test architecture to be able to test plugins
Main infrastructure done by @WerWolv
---------
Co-authored-by: WerWolv <werwolv98@gmail.com>
