UX: Improve usability for received shares

[labkode]

Looking at "shared with me" list now: it's too long and cumbersome to manage for some users. This needs a proper product design and scalability discussion, being able to filter out by different fields (owner, path, ...), hiding and unhiding the shares, filtering by user, group, public links or ocm types.

[labkode]

Related to https://github.com/owncloud/phoenix/issues/3923

[kulmann]

Parts of this are being taken care of in #4989

[dragotin]

I think this is outdated. Pls reopen in case..