PMM-12805 Collstats, indexstats iterate only over collections, not views.

[JiriCtvrtka]

PMM-12805

FB: Percona-Lab/pmm-submodules#3534

[JiriCtvrtka]

Summary after required changes:

1. Func listCollectionsWithoutViews now returns map instead array.
2. User's input collections will end up with error if any of provided collections is view.
3. For autodiscovery it using only collections without views.
4. Ivan was not sure if we need apply this fix even for indexstats. Since problem is with getting cursor for view I also applied this fix to indexstats too to prevent possible problems in future.

[JiriCtvrtka]

@ademidoff View could be part of namespace [database-name].[collection/view/index-name]

I did refactor (possibility to get collections with/without views) and together with this I changed naming to have it more clear. Please take a look once more.