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/coremodel/dashboard/coremodel.go

@@ -0,0 +1,40 @@
+package dashboard
+
+import (
+	"github.com/grafana/thema"
+)
+
+// Coremodel contains the foundational schema declaration for dashboards.
+type Coremodel struct {
+	lin thema.Lineage
+}
+
+// Lineage returns the canonical dashboard Lineage.
+func (c *Coremodel) Lineage() thema.Lineage {
+	return c.lin
+}
+
+func (c *Coremodel) CurrentSchema() thema.Schema {
+	sch, err := c.lin.Schema(currentVersion)
+	if err != nil {
+		// Only reachable if our own schema currentVersion does not exist, which
+		// can really only happen transitionally during development
+		panic(err)
+	}
+	return sch
+}
+
+func (c *Coremodel) GoType() interface{} {
+	return &model{}
+}
+
+func ProvideCoremodel(lib thema.Library) (*Coremodel, error) {
+	lin, err := Lineage(lib)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Coremodel{
+		lin: lin,
+	}, nil
+}