* Restricted users (#4334): initial implementation

* Add User.IsRestricted & UI to edit it

* Pass user object instead of user id to places where IsRestricted flag matters

* Restricted users: maintain access rows for all referenced repos (incl public)

* Take logged in user & IsRestricted flag into account in org/repo listings, searches and accesses

* Add basic repo access tests for restricted users

Signed-off-by: Manush Dodunekov <manush@stendahls.se>

* Mention restricted users in the faq

Signed-off-by: Manush Dodunekov <manush@stendahls.se>

* Revert unnecessary change `.isUserPartOfOrg` -> `.IsUserPartOfOrg`

Signed-off-by: Manush Dodunekov <manush@stendahls.se>

* Remove unnecessary `org.IsOrganization()` call

Signed-off-by: Manush Dodunekov <manush@stendahls.se>

* Revert to an `int64` keyed `accessMap`

* Add type `userAccess`
* Add convenience func updateUserAccess()
* Turn accessMap into a `map[int64]userAccess`

Signed-off-by: Manush Dodunekov <manush@stendahls.se>

* or even better: `map[int64]*userAccess`

* updateUserAccess(): use tighter syntax as suggested by lafriks

* even tighter

* Avoid extra loop

* Don't disclose limited orgs to unauthenticated users

* Don't assume block only applies to orgs

* Use an array of `VisibleType` for filtering

* fix yet another thinko

* Ok - no need for u

* Revert "Ok - no need for u"

This reverts commit 5c3e886aab.

Co-authored-by: Antoine GIRARD <sapk@users.noreply.github.com>
Co-authored-by: Lauris BH <lauris@nix.lv>