replace jquery.minicolors with npm version

[eviljeff]

part of #4370
this library is only used for submitting (editing?) background themes - to select the colours.

[ValentinaPC]

Please add some STR or the label "qa: not needed". Thanks!

[eviljeff]

submit a background theme; color pickers for selecting text colors work.

[ValentinaPC]

Verified this on AMO-dev FF54(Win 7).
Color picker for font and background is working as expected.
@eviljeff : After submitting the theme, the selected background color is not previewed, not sure if this is known or worth fixing.
Please see video:

[eviljeff]

I don't know if it's a known issue, but I doubt it's a bug with AMO (and very unlikely to be due to this library upgrade)

[ValentinaPC]

We can mark this as verified fixed and keep in mind while the new desktop pages are coming in our way.
Thanks!

[muffinresearch]

We can mark this as verified fixed and keep in mind while the new desktop pages are coming in our way.
Thanks!

@ValentinaPC to clarify - the new frontend doesn't cover the developer hub it is just the user pages. Reviewer tools and developer hub are not changing.

[ValentinaPC]

@muffinresearch : Theme submission process will be different, no?