Migrate all UI in solidpod README to solidui README

Review solidpod/README.md and solidui/README.md to migrate all UI releated material from solidpod to solidui, noting that some functionality is yet to migrate from solidpod, but make that note in the solidui README.md for now. E.g. the GrantPermission UI not yet migrated - document it in solidui README.md with a note that it is currently used from solidpod, and remove from solidpod README.md