Schema: get all devenv dashboards passing validation (#37857)

* Strip nulls (again)

* Add stripnulls script

* Add transformations field

* Close FieldConfig struct; proper plugin validating

* s/graph/viz/ field in histogram dashboard

* Use ui.GraphFieldConfig in histogram model

* Add models for stat, gauge, barguage panel plugins

Also toss necessary shared types into cue/ui/gen.cue, with TODOs to move
them appropriately later.

* Add required license headers

* Heap of updates to cue UI components

* Fix barchart types and one old devenv input

* Use the GraphFieldConfig directly for timeseries

* Add models.cue for a few panel plugins

Barchart, state-timeline, and status-history

* Enable the test validating all devenv dashboards!!

* Fix effects of not checking after making comments

* Update packages/grafana-ui/src/options/models.gen.ts

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

* Realign and unalign cue with ts types

* Update devenv test to sniff for null errors

Best option we have right now for helping people to know they need to
strip nulls from devenv dashboards.

* Add speculative default for barchart stacking

* Fixup some dated devenv dashboards

timeline-modes needed to be regenerated with the appropriate tooltip
values included, per typing requirements, and timeline-demo needed to
have the `mode` field removed, as it is not intended to be persisted.

* Add necessary missing options for various panels

* Regenerate devenv dashboards

Co-authored-by: Ryan McKinley <ryantxu@gmail.com>

devenv/dev-dashboards/panel-barchart/barchart-autosizing.json

@@ -354,7 +354,7 @@
         "orientation": "auto",
         "showValue": "auto",
         "text": {
-          "size": 10,
+          "titleSize": 10,
           "valueSize": 25
         },
         "tooltip": {