fix(planner): fix case expr with case operator equal

[b41sh]

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Summary

If the case expression has case_value, compare it with each when_value until one of them is equal.

Fixes #6944

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Name	Status	Preview	Updated
databend	✅ Ready (Inspect)	Visit Preview	Sep 3, 2022 at 2:09AM (UTC)

[xudong963]

How about adding a test case in to https://github.com/datafuselabs/databend/blob/main/tests/logictest/suites/ydb/select1-1.test

select
       case a+1 when b then 111 when c then 222
        when d then 333  when e then 444 else 555 end as col6
from t1
order by col6;

[xudong963]

There are still cases with errors in the logic test that need to be handled @b41sh

[b41sh]

There are still cases with errors in the logic test that need to be handled @b41sh

I will fix them.