schema: Generate Go and Typescript from Thema coremodels (#49193)

* Add go code generator for coremodels

* Just generate the entire coremodel for now

Maybe we'll need more flexibility as more coremodels are added, but for
now this is fine.

* Add note on type comment about stability, grodkit

* Remove local replace directive for thema

* Generate typescript from coremodel

* Update pkg/coremodel/dashboard/addenda.go

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

* Update cuetsy to new release

* Update thema to latest

* Fix enum generation for FieldColorModeId

* Put main generated object at the end of the file

* Tweaks to generated Go output

* Retweak back to var

* Add generated coremodel test

* Remove local replace statement again

* Add Make target and call into cuetsy cmd from gen

* Rename and comment linsrc for readability

* Move key codegen bits into reusable package

* Move body of cuetsifier into codegen pkg

Also genericize the diffing output into reusable WriteDiffer.

* Refactor coremodel generator to use WriteDiffer

* Add gen-cue step to CI

* Whip all the codegen automation into shape

* Add simplistic coremodel canonicality controls

* Remove erroneously committed test

* Bump thema version

* Remove dead code

* Improve wording of non-canonicality comment

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

scripts/drone/steps/lib.star

@@ -1167,6 +1167,16 @@ def ensure_cuetsified_step():
         ],
     }
 
+def verify_gen_cue_step():
+    return {
+        'name': 'verify-gen-cue',
+        'image': build_image,
+        'commands': [
+            '# It is required that code generated from Thema/CUE be committed and in sync with its inputs.',
+            '# The following command will fail if running code generators produces any diff in output.',
+            'CODEGEN_VERIFY=1 make gen-cue',
+        ],
+    }
 
 def end_to_end_tests_deps(edition):
     if disable_tests: