[SPFx] Enable groups in command set extensions, Rename 'id' to '$id' in all manifests#524

VesaJuvonen merged 2 commits intomicrosoft:mainmicrosoft/json-schemas:mainfrom

cmalonzo:user/cmalonzo/spfx/grouping-idcmalonzo/json-schemas:user/cmalonzo/spfx/grouping-idCopy head branch name to clipboard