feat: allow disabling/overriding ObjectFilter in status watcher

[floreks]

With the addition of Filters to the DefaultStatusWatcher it is now possible to apply server-side filtering via labels/fields. This PR allows dropping or overriding client-side filtering with a custom ObjectFilter. In our case we are making sure that every resource in the inventory will contain a static label that can be used for server-side filtering and further client-side filtering is obsolete.

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[karlkfi]

What's the benefit of using a custom object filter?

The built-in filter filters by ID from a map, so it's pretty efficient, just a hashtable lookup. It shouldn't cause any real performance impact.

[floreks]

There might not be many use cases for the custom implementation of ObjectFilter. Being able to disable it completely when relying on server-side filtering is what I was looking for. If that would be something you would be interested in, let me know and I will adjust the code.

PS. From what I can see current AllowListObjectFilter is simply going through the array and doing a struct comparison.

cli-utils/pkg/kstatus/watcher/object_filter.go

Lines 27 to 30 in 4d57e6e

	func (f *AllowListObjectFilter) Filter(obj *unstructured.Unstructured) bool {
	id := object.UnstructuredToObjMetadata(obj)
	return !f.AllowList.Contains(id)
	}

cli-utils/pkg/object/objmetadata_set.go

Lines 56 to 62 in 4d57e6e

	func (setA ObjMetadataSet) Contains(id ObjMetadata) bool {
	for _, om := range setA {
	if om == id {
	return true
	}
	}
	return false

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