Add flag for namespace exception

[yonahd]

Add a flag --exclude which will make kor run on all namespaces except the one included

[linrl3]

@yonahd Could I create a PR for this?

[yonahd]

@linrl3 be my guest

[doryer]

@yonahd Btw, it will be great if it will accept a list + option to exclude resource when running all flag
like kor all --exclude-resource PVC --exclude-namespace foo,bar

[yonahd]

@doryer I think this is similar to this issue #2
We'll get to that soon hopefully