Introduces the `pool_maxsize` parameter to `KeycloakOpenID` and `KeycloakAdmin` classes, allowing control over the underlying connection pool size in the `ConnectionManager`.
Adds corresponding tests to verify the parameter is correctly passed and stored for both synchronous and asynchronous clients.
* refactor: Factor our OpenIdConnectionManager class and deprecate old methods
* refactor: Refactor keycloak uma client to use openid connection manager
* fix: Perform token renewal at 90% of lifetime
* refactor: Add optional openid connection constructor param to keycloak admin
* refactor: Remove auto_refresh_token in favour of automatic refresh on expiry
* refactor: move KeycloakOpenIDConnectionManager to a separate file
* docs: uma additions and fixes
* refactor: rename token_renewal_fraction->token_lifetime_fraction
* refactor: shorten KeycloakOpenIDConnectionManager->KeycloakOpenIDConnection
* docs: incorporate review comments
Andrew Moore
Richard Nemeth
Tobias Genannt
Nuwan Goonasekera
Luca Paganin