Remove unused and duplicated files in js-old (#7082)

* Cleanup v1 build process, application-only

* Remove built-in dapps from build (duplicated)

* User @parity/api instead of local version

* Update references to @parity/abi

* Remove unused js-old api/abi folders

* Remove duplicated v1 jsonrpc

* Cleanup unused routes

* Update manifest with wallet image

* Update wallet logo

* Re-add missing test.sh

* Update rpc mocks

* Update tests for Providers

* Use flex for iframe & status

* Additional cleanups (Home screen for embed)

* Keep statusbar fixed (and non-overallping with dapps)