Update Devfile Registry Support Services to use Go 1.19

Which area/kind this issue is related to?

/area registry

To meet the objective of #1237, we need to ensure our registry support services is using Go 1.19 with updated dependencies.

Update index/generator/go.mod to use Go 1.19
Update index/server/go.mod to use Go 1.19
Update registry-library/go.mod to use Go 1.19
Update tests/integration/go.mod to use Go 1.19
Update dependencies under index/generator/go.mod and index/generator/go.sum and migrate any changes
Update dependencies under index/server/go.mod and index/server/go.sum and migrate any changes
Update dependencies under registry-library/go.mod and registry-library/go.sum and migrate any changes
Update dependencies under tests/integration/go.mod and tests/integration/go.sum and migrate any changes
Refactor all library calls to io/ioutil since it is now deprecated
Update workflows to use Go 1.19
Update requirements under documentation

Update requirements under documentation

No prior documentation in registry-support on Go version requirements, added a Go version badge to the root README.

Go 1.19 changes are for ready for review: devfile/registry-support#212