Custom metrics in example.rules.yaml are not queried and set in CodecoApp CR

Currently, when an ACM user specifies custom metrics in example.rules.yaml, ACM creates the appropriate Prometheus records for the entries. However, when it comes to querying the metrics from Prometheus, ACM currently only copies the hard-coded metrics and not all metrics specified in the example.rules.yaml file [1][2][3]. In addition, the build in the Makefile should be modified so that the CodecoApp CR types automatically contain new fields for the metrics [4].

Our use case requires us to use custom metrics (e.g. latency, throughput, ...) in PDLC so that the PDLC-RL component can optimize pod placement based on these metrics. However, ACM currently doesn't have a way for us to send these custom metrics to PDLC.

[1] https://gitlab.eclipse.org/eclipse-research-labs/codeco-project/acm/-/blob/main/controllers/codecoapp_controller.go?ref_type=heads#L277-312

[2] https://gitlab.eclipse.org/eclipse-research-labs/codeco-project/acm/-/blob/main/controllers/codecoapp_controller.go?ref_type=heads#L219-246

[3] https://gitlab.eclipse.org/eclipse-research-labs/codeco-project/acm/-/blob/main/controllers/codecoapp_controller.go?ref_type=heads#L219-246

[4] https://gitlab.eclipse.org/eclipse-research-labs/codeco-project/acm/-/blob/main/api/v1alpha1/codecoapp_types.go?ref_type=heads#L206-246