Consistent evaluated hline options

[dcaoyuan]

When code hline as:

hline(30, "Upper Band", color.gray, hline.style_dashed)

We will get the evaluated hline options as:

{"color":"#787B86","linestyle":"dashed","overlay":false}

But, if we code hline as:

hline(30, "Lower Band", color = color.gray, linestyle = hline.style_dashed)

We will get the evaluated hline options as:

{"color":{"color":"#787B86","linestyle":"dashed"},"overlay":false}

The result of the first one is correct, and we should also get the same result for the second one.

BTW, it better to include an option "style":"hline" in options.

[alaa-eddine]

Merged in v0.9.0 please check a note I left you on the PR