Hacked color picker inputs should be converted to numeric when loading 2.0 project until full support is added

[ZenithRogue]

In a project I made back in 2015, I use a hacked custom block Define {Color %c}. Now in 3.0, the project load just fine, but wont be able to properly run. I am sure that other projects use this feature (in fact, I have another project here that uses it)

I think the quickest solution with the conversion from 2.0 to 3.0, would be to exchange the color inputs with numeric inputs. This should allow the projects to still respond, but will just use the numeric value of the color instead.

Obviously related to #1030, but I think it warrants its own discussion

[towerofnix]

I believe @apple502j did some WIP work on actually implementing color inputs showing up in the custom blocks themselves (rather than converting them to number inputs): #1030 (comment)

(Btw, that same code looks like it could be tweaked to convert color inputs into number inputs if wanted.)

[ZenithRogue]

The purpose of converting to a number input would be to quickly push out a compatibility update. But color inputs would still be preferable