Optionally ignore some plugin configuration fields

Hi,

We have a use case to optionally exclude certain fields in plugin configurations from deck dump/diff/sync. In our case, we have an external process that dynamically updates the [`acl` plugin's allow list](https://docs.konghq.com/hub/kong-inc/acl/configuration/#config-allow). We still want to be able to specify the `acl` plugin to manage the plugin association with a route but ignore any changes in `config.allow`.

Is this currently possible with any deck features? The expected behaviour would be similar to Terraform's [lifecycle ignore_changes](https://developer.hashicorp.com/terraform/language/meta-arguments/lifecycle#ignore_changes).

No repository files or tests are identified. Start by locating decK's dump, diff, and sync handling for plugin configuration fields, then compare the requested behavior with Terraform's lifecycle ignore_changes and the ACL plugin's config.allow. Done means ignored fields are consistently excluded from the requested operations while other plugin association changes remain managed.

Written by the indexing model from the issue text.