Adding a caching option to keycloak-config-cli

[jkroepke]

Just an idea or concept.

A cache mode would be a good improvement in dev environment to reduce the deploy/configure times.
As I know Keycloak support custom realm attributes. (https://github.com/keycloak/keycloak/pull/3153/files)

A idea to cache the configuration:

• Create a hash (e.g. sha256) for the import json file.
• Create a custom attribute inside the realm with calculated hash
• On next run the utility should recalculate the hash if the json with in saved attribute and if the hash is the same skip the whole reconfiguration process.

This behavior should be an opt-in mechanism.

[borisskert]

Sounds really good. I will have a look at this.