feat(cli): add/set/remove worker tags (#2266)

* adds CLI commands for add/set/removing worker tags, and respective tests
* adds StringSliceMapVar Flag to convert a string from the CLI to a map[string][]string value

internal/api/genapi/input.go

@@ -810,7 +810,13 @@ var inputStructs = []*structInfo{
 				PostType: "worker_generated_auth_token",
 			},
 		},
-		pluralResourceName:  "workers",
+		pluralResourceName: "workers",
+		sliceSubtypes: map[string]sliceSubtypeInfo{
+			"WorkerTags": {
+				SliceType: "map[string][]string",
+				VarName:   "apiTags",
+			},
+		},
 		createResponseTypes: true,
 		recursiveListing:    true,
 		versionEnabled:      true,