[Bug Report] hookContext has invalid casing for JS plugin

[puc9]

Describe the bug It's not very clear what is the format for a JS plugin input. Should it follow the JSON casing or should it follow the object casing?

The object in question: https://github.com/WithoutPants/stash/blob/f64d5436dba6362116163c45d28688b0327cbbfd/pkg/plugin/common/msg.go#L113-L120

// HookContext is passed as a PluginArgValue and indicates what hook triggered
// this plugin task.
type HookContext struct {
        ID          int         `json:"id,omitempty"`
        Type        string      `json:"type"`
        Input       interface{} `json:"input"`
        InputFields []string    `json:"inputFields,omitempty"`
}

Note Type vs type.

When trying to get the type in JS this fails: input.Args.hookContext.type

A simple test JS plugin that reacts on hooks:

log.Info(JSON.stringify(input.Args));
log.Info(input.Args);
log.Info(Object.getOwnPropertyNames(input.Args));
log.Info(input.Args.hasOwnProperty('hookContext'));
log.Info(Object.getOwnPropertyNames(input.Args.hookContext));
log.Info(input.Args.hookContext.hasOwnProperty('type'));
log.Info(input.Args.hookContext.hasOwnProperty('Type'));

return { Output: 'ok' };

results in these log entries (I've reversed the order to match the code):

Info    [Plugin] {"hookContext":{"ID":123,"Type":"Scene.Create.Post","Input":null,"InputFields":[]}}
Info    [Plugin] {"hookContext":{"id":123,"type":"Scene.Create.Post","input":null}}
Info    [Plugin] hookContext
Info    [Plugin] true
Info    [Plugin] ID,Type,Input,InputFields
Info    [Plugin] false
Info    [Plugin] true

Note the difference in casing when using stringify.

This may have been introduced in #4631