The ocis module version is v2 instead of v7

## Describe the bug
The ocis module version is v2 instead of v7 in a `go.mod` file it broke the dependencies between the `osic` and `reva`
There are several services in a `reva` that use `github.com/owncloud/ocis/v2/ocis-pkg/registry` and pointed to the `ocis/v2.0.0`
https://github.com/cs3org/reva/blob/ea319ad6ac575eb725be92f9c0be8a6f7fe84fbd/go.mod#L64

It could lead to unexpected side effects because the default registry for the v2 is `mdnsr`

Releasing modules https://go.dev/wiki/Modules#releasing-modules-v2-or-higher