Add support for refreshing the access token of an account

**Related command**
`az account`

**Is your feature request related to a problem? Please describe.**
Some scenarios require refreshing the cached access token of an account, for example when user's group membership changes as a consequence of [PIM for Groups](https://learn.microsoft.com/en-us/entra/id-governance/privileged-identity-management/concept-pim-for-groups).

**Describe the solution you'd like**
Provide a mechanism to refresh the cached access token of an account e.g. `az account refresh-access-token`.

**Describe alternatives you've considered**
Waiting for token expiration or performing `az logout` and `az login`.