[Step 4] Update namespace statistics after personal snippet update/removal
At the moment, with all the other issues we've implemented in the related epic, we have introduced the logic to update any update/removal made to a project snippet.
Nevertheless, we need to include in the author's RootStorageStatistics
any update to personal snippets. For that, we need to rethink all the code we introduced because it doesn't work well with personal snippets.
We're going to replace some of the snippets' logic and use the concern UpdateProjectStatistics
along with other modifications to include personal snippets changes.
This way, all the logic will be gathered in the SnippetStatistics
model, and avoid spreading it around in different services.