Explorer: Add upload/download/space benchmarks back into the host route

[telestrial]

At the time of this writing, we're replacing Sia Central's api with explored for the hosts route in the explorer (siascan). Everything is ready to go with that except for benchmark fields of upload_time, download_time, and data_size. Once this benchmarking work is done in explored, we need to go in, uncomment what's in HostPricing.tsx and adjust the fields, if the property names change.