[v9.17.0] Maestro v9 to coexist with other Game Room providers

[hspedro]

• refactor(controller): do not fail scheduler if namespace exists

When creating a scheduler, we fail if the namespace already exists. This is problematic if there are other GR providers running at the same namespace, like maestro v10 for example. Thus, don't fail scheduler creation if namespace exists.

• refactor(controller): do not delete namespace on scheduler delete

There can be other GR providers running into the same namespace, thus we don't want to cascade delete the k8s namespace on scheduler deletion

• refactor(watcher): filter pod events by heritage label

There can be other resources/pods running in the namespace that are not managed by Maestro. In that case, we want to filter the watcher to only receive pod events from the ones created by v9

[coveralls]

coverage: 78.143% (+0.06%) from 78.079%
when pulling 597ef9c on feat/filter-events-by-heritage
into 4338d9d on v9.16.0.

[coveralls]

coverage: 78.077% (-0.002%) from 78.079%
when pulling 367abb6 on feat/filter-events-by-heritage
into 4338d9d on v9.16.0.

[reinaldooli]

Wdyt about adding a configuration option for the namespace deletion? My concern here is that when not having other GR providers, it's good to delete te namespace.

[joaobologna]

LGTM

[joaobologna]

is this intended?