This matches InfluxDB Cloud. The pagination was not exposed to the API,
but meant that API requests were limited to the default 20 pages.
Closes: #21407
* Move tenant.Service unit tests into its package
* Delete the top-level TenantService interface now that it's not used.
* Move helper funcs for setting up test stores into testing pkg
* Delete duplicate implementations scattered through the codebase
* Move error assertions into store-creation helpers
I did this with a dumb editor macro, so some comments changed too.
Also rename root package from platform to influxdb.
In interest of minimizing risk, anyone importing the root package has
now aliased it to "platform" so that no changes beyond imports were
necessary in those files.
Lastly, replace the old platform module to local path /dev/null so that
nobody can accidentally reintroduce a platform dependency while
migrating platform code to influxdb.