A TestCase which is not annotated to be in group DB will not allow access to the database connection.
This is necessary to categorize unit test and avoid duplicate test case execution - it also allows us to closely review unit test implementations to identify unnecessary db calls.

* removes OC_Helper::mb_substr_replace and OC_Helper::mb_str_replace
* keeps public interface wrapper working as expected

* ref #4774

No injection of userfolders etc. Only generic DI components
(IRootFolder) etc should be used to make sure we can also run this from
the cli

The share manager etc should not care about filtering stuff. They should
return what is asked for them.

To make sure hooks are always fired and child entries are always
cleaned. This logic is moved to the share manager.

* Updated unit tests

this replaces shared etag propagation

1. Allows it to use the more secure CSP rules of the AppFramework.
2. Adds some unit tests.

Removed leftover print statement

This reduces a lot of the autoloader magic and makes sure that we
generate full paths in the autoloader.

OCS -> ShareManager -> DefaultShareProvider