Fix path on Permission's entity search method

Entities path was updated to base/self instead of all/this and this was
missed for Permission entity because the relevant PR was open.
Merge pull request #1480 from elyezer/fix-permission-path

Fix path on Permission's entity search method
(API) Port old tests for hosts

Significantly update the definition of class `Host`: modify fields and override
the `build` method to properly create dependent entities. Enable CRUD tests for
hosts in module `test_multiple_paths`. Drop old CRUD tests for hosts.

Slightly clean up module `test_host_v2`.

Fix #1446.