Allow charge scale to be customizable

[SaintWish]

Allow the charging scale for weapons to be customizable with a cvar, like it was in the MSC's alpha. Probably best to make the cvar ms_chargebar_scale as it was in the MSC's alpha.
Expose charge scale to the scripting system.

[Aze-M]

Could you elaborate more on what is wanted here?

[Aze-M]

After talking on Discord: Likely best to expose charge times on a per-weapon basis to the script side so it can be controlled on a weapon per weapon basis.
Best to do this after angelscript.