jobqueue: rename to worker

This package does not contain an actual queue, but a server and client
implementation for osbuild's worker API. Name it accordingly.

The queue is in package `store` right now, but about to be split off.
This rename makes the `jobqueue` name free for that effort.

internal/worker/json.go

@@ -0,0 +1,31 @@
+package worker
+
+import (
+	"github.com/google/uuid"
+
+	"github.com/osbuild/osbuild-composer/internal/common"
+	"github.com/osbuild/osbuild-composer/internal/osbuild"
+	"github.com/osbuild/osbuild-composer/internal/target"
+)
+
+type errorResponse struct {
+	Message string `json:"message"`
+}
+
+type addJobRequest struct {
+}
+
+type addJobResponse struct {
+	ComposeID    uuid.UUID         `json:"compose_id"`
+	ImageBuildID int               `json:"image_build_id"`
+	Manifest     *osbuild.Manifest `json:"manifest"`
+	Targets      []*target.Target  `json:"targets"`
+}
+
+type updateJobRequest struct {
+	Status common.ImageBuildState `json:"status"`
+	Result *common.ComposeResult  `json:"result"`
+}
+
+type updateJobResponse struct {
+}