Add wire_digitalscreen_draw_rate and wire_digitalscreen_net_bandwidth convars

[AlexALX]

This convar multiply all digital screen limits in sync, so wire_digitalscreen_rate 10 make it work exactly 10x faster. Fixes#3670

[AlexALX]

Tell me if you don't like this way, and then i'll need create 4 separate convars for it.

[AlexALX]

With wire_digitalscreen_rate 10 its possible to play GIF simple animations!

Without that convar its barelly possible to display anything...

And since by default nothing changed, and digital screen keep working as-is, it might be good option to include, then users will decide change or not.

[Astralcircle]

I guess you should limit it's max value to something like 10 because bigger values can probably cause net overflows

[thegrb93]

This won't get the updated value. Need to use function params. updateBW(cvar, old, new) new = tonumber(new) or default

[Astralcircle]

:Get* functions already return updated value in change callbacks

[thegrb93]

Did gmod devs fix that? Cuz I did a refactor recently to get around that issue.

[AlexALX]

I guess you should limit it's max value to something like 10 because bigger values can probably cause net overflows

Hm, then i guess better to make two convars, one for net limit, second for draw limit. netrate / drawrate with bit different values. or not sure, will do some tests bit later

[AlexALX]

So i did split this into two convars how:

wire_digitalscreen_draw_rate - purelly for draw rate speed
wire_digitalscreen_net_bandwidth - set global bandwidth limit, individual devices always have 50% of global rate

[Astralcircle]

Clamp convar max value and minimum value instead of using math.Clamp