Have helm chart delete CRD or add option to not create CRD

[lee0c]

Deleting a helm release of keda & then re-installing fails currently as helm does not delete CRDs by default. There are a few possible work arounds:

1. Add a values file flag that sets whether or not CRDs are created
2. Add a hook that cleans up the ScaledObject CRD post-deletion
3. Add a hook that cleans up the ScaledObject CRD pre-install (wipes old versions if they exist)

Might want to do 1. & one of 2. or 3. - since killing the ScaledObject CRD will kill deployed ScaledObjects afaik, adding in option 1. & making either 2. or 3. dependent on that value will give users a use case where they don't touch their deployed ScaledObjects while making other edits

Haven't checked the func cli behavior for this issue but the func cli also doesn't offer a command to delete/remove keda from a cluster so at that point it's manual anyway.