Add support for generic filters in FindUsers and FindGroups

[glpatcern]

Continuation of #247 : this is a breaking change to be able to supply filters per type and by query when looking for Users and Groups.
cc @rhafer @jessegeens @diocas

[glpatcern]

Reviewing myself, I changed filter to filters to conform to the rest of the CS3 APIs' convention for repeated fields.

[glpatcern]

@rhafer unless you shout in the next couple of days we'd merge this and you may go for a PR such as opencloud-eu/reva#345 to align - conceptually this is part of the same breaking change.

[rhafer]

@rhafer unless you shout in the next couple of days we'd merge this and you may go for a PR such as opencloud-eu/reva#345 to align - conceptually this is part of the same breaking change.

Sorry I was away the last couple of days, so I couldn't look into this. In general I am fine with the change. But please lets follow some basic proto language guide lines with regards to the field numbers and names. (See my inline comments)

[glpatcern]

Sorry I was away the last couple of days, so I couldn't look into this. In general I am fine with the change. But please lets follow some basic proto language guide lines with regards to the field numbers and names. (See my inline comments)

No problem at all, and no rush. About following the protobuf guidelines when introducing breaking changes, I should note that we have so far never followed them, on the basis that we are still at version v0.0.0-date-commit, which by SemVer does not guarantee any forwards or backwards compatibility. After all, those APIs support single-site deployments, and the need for backwards compatibility logic across different API versions is low to non-existent.

That said, I would be keen to tag v1.0.0 some time soon (maybe at next CS3 workshop?), as in the last years the APIs have been pretty stable. And after that, your recommendations perfectly hold. For this time, I prefer to not make this change "special", as it's not different from many other similar changes.

[rhafer]

Sorry I was away the last couple of days, so I couldn't look into this. In general I am fine with the change. But please lets follow some basic proto language guide lines with regards to the field numbers and names. (See my inline comments)

No problem at all, and no rush. About following the protobuf guidelines when introducing breaking changes, I should note that we have so far never followed them, on the basis that we are still at version v0.0.0-date-commit,

Hm, true 😄 you have a point there. As said, otherwise I am fine with the change 👍

[glpatcern]

Given the last comments and that we verbally validated this change with @jessegeens, I'm merging it.