add email search index (#276)

cmd/rekor-cli/app/pflags.go

cmd/rekor-cli/app/pflags_test.go

cmd/rekor-cli/app/search.go

go.mod

go.sum

openapi.yaml

pkg/api/error.go

pkg/api/index.go

pkg/generated/models/search_index.go

pkg/generated/restapi/embedded_spec.go

pkg/pki/minisign/minisign.go

pkg/pki/pgp/pgp.go

pkg/pki/pgp/pgp_test.go

pkg/pki/pkcs7/pkcs7.go

pkg/pki/pkcs7/pkcs7_test.go

pkg/pki/pki.go

pkg/pki/ssh/ssh.go

pkg/pki/x509/x509.go

pkg/types/rekord/v0.0.1/entry.go

pkg/types/rpm/v0.0.1/entry.go