InfluxDB 2 OSS: Remove UI limit when switching organizations

__Proposal:__
Remove the limit to the number of organisations you can select via the UI 'Switch Organizations' menu option.

__Current behavior:__
When switching organisations only 20 organisations are displayed in the UI. If you create more than 20 organisations there is no way to switch to an organisation if it does not appear in that list.

__Desired behavior:__
When logged in as the main admin user I would like to be able to switch to any organisation via the UI, even if more than 20 organisations have been created.

__Alternatives considered:__
The only way to switch an organisation that is outside the initial 20 organisation limit is to create a user for the new organisation and log into that organisation as that user.

__Use case:__
As an admin user I would like the ability to quickly and easily switch between all organisations via the UI. This is to help with admin tasks such as creating tokens in the new organisations, copying dashboards between organisations, etc.

Start by tracing the UI “Switch Organizations” menu and the organization list it loads. Reproduce the issue with more than 20 organizations, then verify that every organization can be selected and that the menu still behaves correctly.

Written by the indexing model from the issue text.