Add support to generate (on the fly) and load sfxr

[GWRon]

Add support to load .sfxr files or generating it on request via either LoadSfxrSound(preset, seed) or LoadSound() or TSoloudSound.Load() (then via an encoded key: GenerateSfxrUrl(preset:int, seed:Int).

@blitzmax-itspeedway-net brought up the idea of SFXR-support first and made a wonderful and already working repo there:
https://github.com/blitzmax-itspeedway-net/retro.audio

That Repo contains all the samples to try it out. (just replace import retro.audio with Import Audio.AudioSDL for the sake of being)

Yet I think it does not add a further dependency, so would do well right in the audio.mod itself.

[GWRon]

If preferred I could also introduce a new Type:

Type TSoloudSfxrPresetConfig
  Field preset:Int
  Field seed:Int
End Type

And use this instead of packing it in a long and this then in a String.

[GWRon]

taken from scaremongers samples and extended to show simply loading:

' 	SFXR LoadSound( TBank ) Example
'   (c) Copyright Si Dunford, September 2022, All Rights Reserved. 
'   VERSION: 1.1

' This example shows how an SFXR resource file can be loaded from a TBank

SuperStrict

Import Audio.AudioSDL

AppTitle="SFXR LoadSound( TBank ) Example"
Graphics 320, 200

'bank test
'Local bank:TBank = New TBank.Load( "powerup.sfxr" )
'Local sound:TSound = TSoloudSound.Load( bank, SOLOUD_SOUND_SFXR   )
'direct test
Local sound:TSound = LoadSound(GenerateSfxrUrl(8, 22334), SOLOUD_SOUND_SFXR)

Repeat
    Cls
	DrawText( "Press SPACE to play sound", 5, 5 )
    If KeyHit( KEY_SPACE )
        Local channel:TChannel = AllocChannel()
		PlaySound( sound, channel )
    EndIf
    Flip
	Delay( 1 )
Until KeyHit( KEY_ESCAPE ) Or AppTerminate()