feat: configure standardResources via controller configmap

[inishchith]

Better way to configure the memory and CPU resource requests

closes #1487

Sample configmap

apiVersion: v1
kind: ConfigMap
metadata:
  name: numaflow-controller-config
data:
  controller-config.yaml: |+
    defaults:
      containerResources: |
        limits:
          memory: "256Mi"
          cpu: "200m"
        requests:
          memory: "128Mi"
          cpu: "100m"

[vigith]

Is standardResources only for UDF containers?

[inishchith]

Is standardResources only for UDF containers?

@vigith - Not just UDF. All init and main containers for vertex, daemon, redis_buffer_service.

[whynowy]

@inishchith - It looks good to me, can you please:

1. Add the new config to https://github.com/numaproj/numaflow/blob/main/config/base/controller-manager/numaflow-controller-config.yaml#L7, use the default resource settings;
2. Add some doc to https://github.com/numaproj/numaflow/blob/main/docs/operations/controller-configmap.md, also add the new config to https://github.com/numaproj/numaflow/blob/main/docs/operations/numaflow-controller-config.yaml.
3. Appreciate if you could add a config_test.go to cover the unit tests (unit tests for config.go are missing, you can add the one for the new function you added, but always welcome if you could cover more).

[inishchith]

@whynowy Thanks!

I have updated the docs and config.
I have also added minimal tests that covers the newly introduced method. Covering the config file might require refactoring some LoadConfig, which I think might diverge from the goal of this change list. Let me know your thoughts.

[whynowy]

LGTM, thanks!