Form conversion: Compute/Infra/PXE ISO Datastores - Add ISO Datastores

[h-kataria]

Convert form to use DDF/React and API - parent issue #6825

Location: Compute/Infra/PXE ISO Datastores

Form: Add ISO Datastore
API: ManageIQ/manageiq-api#992

[DavidResende0]

There's no API endpoint for this select field right now and the data currently comes from here:

manageiq-ui-classic/app/controllers/pxe_controller/iso_datastores.rb

@edit[:emses] = ManageIQ::Providers::Redhat::InfraManager
                    .without_iso_datastores
                    .order(:name)
                    .pluck(:name, :id)

I've made an issue in the API repo to address it (ManageIQ/manageiq-api#1020) but alternatively I could add some code to the select that would compare all the current ISO datastores (/api/iso_datastores) with all the Infrastructure Management providers (/api/providers?collection_class=ManageIQ::Providers::Redhat::InfraManager) to filter out the "unused" providers.

Thoughts? @gtanzillo @Fryguy

[DavidResende0]

@kavyanekkalapu or @Fryguy this issue can be closed since the form is merged