[BUGFIX] Remove baseUri from the Storage

The baseUri in the Storage has a Getter and is the
only thing initialized in the "processConfiguration"
method of a Storage. Due to the fact that "baseUri"
is not a field in the storage-table this never could
be set, and therefore always has been null.

It appears that this has been a left over from earlier
days and it is save to remove this, since the getter
always returned NULL (and as a result was unusable).
In addition the processConfiguration and its signals
are removed as they have and never had an effect anyhow.

Change-Id: I3416ee393a1eb3d0f1ea5fc588a351bb1555cdba
Releases: 6.2
Resolves: #56783
Reviewed-on: https://review.typo3.org/28271
Reviewed-by: Steffen Ritter
Tested-by: Steffen Ritter