* ui: Add data-source component and related services (#6486)
* ui: Add data-source component and related services:
1. DataSource component
2. Repository manager for retrieving repositories based on URIs
3. Blocking data service for injection to the data-source component to
support blocking query types of data sources
4. 'Once' promise based data service for injection for potential
fallback to old style promise based data (would need to be injected via
an initial runtime variable)
5. Several utility functions taken from elsewhere
- maybeCall - a replication of code from elsewhere for condition
calling a function based on the result of a promise
- restartWhenAvailable - used for restarting blocking queries when a
tab is brought to the front
- ifNotBlocking - to check if blocking is NOT enabled
* Move to a different organization based on protocols
* Don't call open twice when eager
* Workaround new ember error for reading and writing at the same time
* Add first draft of a README.mdx file
John Cowen