`DataTypeFactory::get` locks a mutex inside shared a context, there was a case when many threads were locked inside it

https://pastila.nl/?0043b3e6/c557368f4cf0eb87a3c6f2cc162bc693

It is not clear which thread locked the mutex for a long time. However, it may be possible to lock less inside `DataTypeFactory::get`.
{
    auto lock = getLock();
    return shared->user_scripts_path;
}
String Context::getUserDefinedPath() const
{
    auto lock = getLock();
    return shared->user_defined_path;
}
Strings Context::getWarnings() const
{
    Strings common_warnings;
    {
        auto lock = getLock();
        common_warnings = shared->warnings;
    }
    for (const auto & setting : settings)
    {
        if (setting.isValueChanged() && setting.isObsolete())
        {
            common_warnings.emplace_back("Some obsolete setting is changed. "
                                         "Check 'select * from system.settings where changed' and read the changelog.");
            break;
        }
    }
    return common_warnings;
}
VolumePtr Context::getTemporaryVolume() const