#93 add form generator

[PhilippMDoerner]

This PR adds a generic proc that generates a Box with a List of Widgets for every field in a given object.
Which mostly means for every field in a given <Widget>State.

This autoform was only used in the Scale.nim example for now, other examples shall be updated in a separate PR to keep these small and easily reviewable.

The reasoning for why I chose a generic proc rather than writing a generic viewable I laid out in #93

This PR actually only adds an autoform.nim file, but as this branch is one that branched off the one for #90 it contains the same changes as that one.

This PR depends on #90 as #90 provides the scale.nim example and that was what I used as reference to implement this.

As per the usual, it's all up for change regardless. Even if I already have #95, I should be able to relatively simply adjust that to whatever we decide here as I'm semi-sure the concept of "take in a state, iterate over it and spit out a widget based on that" will remain.

closes #93

[PhilippMDoerner]

Okay, this is a first draft that basically recreates the sidebar as before.
Well almost.
I don't really control the order of this one so the marks field is not at the end of the list, it's somewhere in the middle.
Also I added a DropDown field so you can decide the ScalePosition of a given mark.

My next step will be to see if I can't move from a custom toFormField method to something that fully generates a proc like that just from a given type.

[PhilippMDoerner]

@can-lehmann I've got a... let's say first draft working for auto-generating ExpanderRows per entry for a given type seq[T].

I'm honestly not too sure what to make of this.
I can either pretty this up, or we just remove it again and instead implement custom toFormField procs for every custom data type we have in a seq.
Might be less of a headache (and code) overall because the generic manner of this is starting to get somewhat abstract, but on the other hand having to write your own toFormField for custom data types every time might be repeated effort.

Then again, I don't think this should happen too often.
Thoughts?

[PhilippMDoerner]

I've decided to just move over to the approach where you defined a custom toFormField for every custom type you have.
Generating forms for every normal type in an action Row is way too annoying.

Added a general custom toFormField for the datatype of sizeRequest though since that's from baseWidget and we can expect it everywhere.

[can-lehmann]

#91 (comment) also applies here, so I would personally prefer to merge this after the JSON discussion and then move any discussions & changes to #95.

[PhilippMDoerner]

Ohhh merge this into #95 and close this PR? Works for me.
I'd proclaim the JSON discussion as finished with the new dummy "toFormField" proc that acts as a fallback when nothing else works.

[PhilippMDoerner]

Basically, if you tell me now this looks okay with the new toFormField for any types that aren't caught by any of the other toFormFields, I'll merge this branch into #95 and close this PR

[can-lehmann]

Ohhh merge this into #95 and close this PR? Works for me.

Sounds good.

[PhilippMDoerner]

Merged into branch of #95, closing this PR.