[REQ][Java] Support refreshing access tokens

[kota65535]

Is your feature request related to a problem? Please describe.

Current generated Java clients only can be configured with a static access token. This does not work well for integrations where tokens are short-lived and need to be refreshed.

Describe the solution you'd like

Java clients can have a configuration for a supplier function to get an access token. In this function, we can implement a mechanism to refresh the access token.

Describe alternatives you've considered

I'm using custom templates and so far it is working well, but it makes diffucult to upgrade the openapi-generator version.

Additional context

Similar to #14068

[kota65535]

Fixed partially with RestTemplate library