Tests: convert multihost/alltests/test_cache_testing to system/memory_cache

[patriki01]

Converted another bunch of tests.

[jakub-vavra-cz]

LGTM

[alexey-tikhonov]

I know this is merely a port of 821455c that in turn is a port of bash(?) tests, but:

• none of tests seems to have anything to do with 'memory cache' (as prefix suggests)
• tests tend to rely on internal implementation details too much, imo
• tests descriptions don't describe what is being tested in plain words but rather retell code
• too many overlaps (in particular, it doesn't make sense to run those tests against all providers)
• I would suggest starting with a testing plan - "Testing of persistent caching" - describing use cases based on documentation, and then covered those cases

[danlavu]

Most of the tests overlap

https://github.com/SSSD/sssd/blob/master/src/tests/system/tests/test_sss_cache.py

Except the last two tests and those I think should be consolidated into one so it's cleaner. More detail in the comments.

Not part of this PR, but a note.

What we are missing is the functional part of the cache tests. We have one test that sort of does it.

test_authentication__offline_login

It configures parameters and doesn't use the default. We should always have a vanilla functional test.

[danlavu]

I've been doing some house keeping/auditing of tests in the new test frame. Please take a look at this pull request, #7160

A lot of tests that you have ported, thank you for porting them. They're going to be renamed and need to be re-evaulted because it may have been a poor test case to begin with.