Add support for alternative script packs

[Yoooi0]

<video name>.funscript
<video name>.pitch.funscript

<video name>.<pack name>.funscript
<video name>.<pack name>.pitch.funscript

HereSphere scene api can return multiple stroke scripts, so have to handle multiple scripts per axis ignoring the name
Ability to switch pack or single script from UI. Fancy combobox when clicking the file path? Or just simple menu Script -> Change -> <script list>/<pack list>
On path change reset?

Script lookup probably has to return Dictionary<DeviceAxis, IEnumerable<IScriptResource>>, or might have to make a ScriptCollection class that holds scripts and pack names with helper methods.