Scheme Label form follow-up

[johnatawnclementawn]

I still can't add new labels, and the dropdowns powering the editor still do not show their selection if creating a new label.

Also I'm noticing this warning in the console now:

runtime-core.esm-bundler.js:202 [Vue warn]: Extraneous non-props attributes (pt) were passed to component but could not be automatically inherited because component renders fragment or text root nodes. 
  at <ReferenceDatatypeEditor value=null options= [{…}] multi-value=false  ... > 
  at <ReferenceDatatype value=null mode="edit" multi-value=false  ... > 
  at <LabelEditor value= {tileid: '7b559cf4-77a1-49b3-9116-aabffd464bd3', resourceinstance: 'b73e741b-46da-496c-8960-55cc1007bec4', nodegroup_id: 'ef87ac28-11de-11ef-9493-0a58a9feac02', sortorder: 0, provisionaledits: null, …} onUpdate=fn<update> > 
  at <SchemeLabel mode="edit" tileId="7b559cf4-77a1-49b3-9116-aabffd464bd3" onUpdated=fn<onSectionUpdate>  ... > 
  at <SchemeEditor key=0 editor-max=true editor-form="label"  ... > 
  at <SplitterPanel key=1 size=33 min-size=33  ... > 
  at <Splitter style= {height: '100%'} > 
  at <SchemePage onVnodeUnmounted=fn<onVnodeUnmounted> ref=Ref< Proxy(Object) {__v_skip: true} > > 
  at <RouterView> 
  at <SplitterPanel min-size=25 style= {overflow-y: 'auto'} tabindex="-1" > 
  at <Splitter style= {height: '100%', overflow: 'hidden'} pt= {gutter: {…}} > 
   at <HierarchySplitter key=0 > 
  at <App>

Originally posted by @chrabyrd in #169 (review)

[johnatawnclementawn]

Resolved in #169