databases/clickhouse: Update to 19.5.3.8

• Clickhouse requires now a compiler that understands C++17.

While I'm here:

• Set the TEST option as non-default and convert all runtime dependencies of that option to default ones. The former description was somewhat misleading because the TEST option only installed two additional Python scripts.
  
  The test query datasets in %%DATADIR%%-test/ and the previously mentioned Python scripts were always installed regardless if TEST was set/unset because they are part of the normal release installation. This also would lead to build failures if the TEST option was disabled. [1]

• Use the TEST option for compiling and testing of additional tests by enabling -DENABLE_TESTS (instead of introducing a new option with another name for it). [1]

• Also mark the TEST option as broken when building on FreeBSD 13.0-CURRENT with Clang 8 because it segfaults with an assertion error in function "getZExtValue()".

• Pet portlint a bit by placing some variables to their intended locations.

Changelog:

https://github.com/yandex/ClickHouse/blob/v19.5.3.8-stable/CHANGELOG.md

PR: 237318
Submitted by: proler@gmail.com (maintainer)
Approved by: maintainer [1], mentors (implicit)