Add permissions specific to reading usage and limits in Cloud

__Proposal:__
Add a permissions set specific to reading usage data and limits in InfluxDB Cloud. This will likely affect the following user-facing touch points:

- Creating tokens in the UI
- Creating tokens in the CLI (possibly adding a `--read-usage` flag)
- Creating tokens via the API

__Current behavior:__
Currently, only All-Access tokens have the permissions necessary to hit the usage endpoints. Understandably, users don't want to grant that much access for a simple request.

__Desired behavior:__
The ability to create a token with read-only access to usage metrics and usage limits.

__Use case:__
Limit exposure for simple requests.

Start by tracing token creation in the UI, CLI, and API, then inspect how the usage endpoints check permissions. Done means a token can be created with read-only access to usage metrics and limits through the listed touch points, without requiring an All-Access token.

Written by the indexing model from the issue text.