Introduce coremodels framework (extracted from intent-api) (#47653)

* Copy over most of coremodel from intent-api branch

* Fix import paths

* Fix incorrect provider name

* Add root compgen file, fixup componentroot.yaml

* go mod tidy

* Remove compgen for now

* Add dashboard coremodel

* Remove datasource coremodel, for now

* Tweak comments on dashboard struct model

* devenv: add dashboard testing directly

* Fixup dashboard schema for openness, heatmap

* Update Thema to tip

* Fix wire/registry references

* Fix hclog version

pkg/framework/coremodel/interface.go

@@ -0,0 +1,25 @@
+package coremodel
+
+import (
+	"github.com/grafana/thema"
+)
+
+// Interface is the primary coremodel interface that must be implemented by all
+// Grafana coremodels.  A coremodel is the foundational, canonical schema for
+// some known-at-compile-time Grafana object.
+//
+// Currently, all Coremodels are expressed as Thema lineages.
+type Interface interface {
+	// Lineage should return the canonical Thema lineage for the coremodel.
+	Lineage() thema.Lineage
+
+	// CurrentSchema should return the schema of the version that the Grafana backend
+	// is currently written against. (While Grafana can accept data from all
+	// older versions of the Thema schema, backend Go code is written against a
+	// single version for simplicity)
+	CurrentSchema() thema.Schema
+
+	// GoType should return a pointer to the Go struct type that corresponds to
+	// the Current() schema.
+	GoType() interface{}
+}