Codegen: Isolate schema generation code (#98742)

* Create go.mod files for plugins and core kinds

* Update go work and main go.mod dependencies

* Update pfs import

* Missing update of pfs dependency

* Remove fixed cuelang dependency

* Update codeowners

* Update workspace

* Update Dockerfile

* Missing go.mod codeowner

* Use intermediate kin-openapi dependency to make all workspaces to work

pkg/plugins/codegen/pfs/errors.go

@@ -0,0 +1,26 @@
+package pfs
+
+import "errors"
+
+// ErrEmptyFS indicates that the fs.FS provided to ParsePluginFS was empty.
+var ErrEmptyFS = errors.New("provided fs.FS is empty")
+
+// ErrNoRootFile indicates that no root plugin.json file exists.
+var ErrNoRootFile = errors.New("no plugin.json at root of fs.fS")
+
+// ErrInvalidRootFile indicates that the root plugin.json file is invalid.
+var ErrInvalidRootFile = errors.New("plugin.json is invalid")
+
+// ErrInvalidGrafanaPluginInstance indicates a plugin's set of .cue
+// grafanaplugin package files are invalid with respect to the GrafanaPlugin
+// spec.
+var ErrInvalidGrafanaPluginInstance = errors.New("grafanaplugin cue instance is invalid")
+
+// ErrInvalidLineage indicates that the plugin contains an invalid lineage
+// declaration, according to Thema's validation rules in
+// ["github.com/grafana/thema".BindLineage].
+var ErrInvalidLineage = errors.New("invalid lineage")
+
+// ErrDisallowedCUEImport indicates that a plugin's grafanaplugin cue package
+// contains that are not on the allowlist.
+var ErrDisallowedCUEImport = errors.New("CUE import is not allowed")