* MSan added with fixes for libc++
* libc++ sepatare build
* add libc++ to ci
* libstdc++ in CI
* libcpp and msan to external projects
* std::sqrt
* awful_hack(ci): install whole llvm instead of libc++ in terrible way for test containers
* Adding ddeb packages for teststages and repos
* libc++ more for test container
* save some money on debug
* colored coredumps
* revert ci
* chore(ci): collect asan ubsan and libc++ build with mtr and regression status ignored
There were numerous memory leaks in plugin's code and associated code.
During typical run of MTR tests it leaked around 65 megabytes of
objects. As a result they may severely affect long-lived connections.
This patch fixes (almost) all leaks found in the plugin. The exceptions
are two leaks associated with SHOW CREATE TABLE columnstore_table and
getting information of columns of columnstore-handled table. These
should be fixed on the server side and work is on the way.
