Stop linking plugins to the server executable on Windows.
Instead, extract whole server functionality into a large DLL, called
server.dll. Link both plugins, and small server "stub" exe to it.

This eliminates plugin dependency on the name of the server executable.
It also reduces the size of the packages (since tiny mysqld.exe
and mariadbd.exe are now both linked to one big DLL)

Also, simplify the functionality of exporing all symbols from selected
static libraries. Rely on WINDOWS_EXPORT_ALL_SYMBOLS, rather than old
self-backed solution.

fix compile error

replace GetProcAddress(GetModuleHandle(NULL), "variable_name")
for server exported data with actual variable names.

Runtime loading was never required,was error prone
, since symbols could be missing at runtime, and now it actually failed,
because we do not export symbols from executable anymore, but from a shared
library

This did require a MYSQL_PLUGIN_IMPORT decoration for the plugin,
but made the code more straightforward, and avoids missing symbols at
runtime (as mentioned before).

The audit plugin is still doing some dynamic loading, as it aims to work
cross-version. Now it won't work cross-version on Windows, as it already
uses some symbols that are *not* dynamically loaded, e.g fn_format
and those symbols now exported from server.dll , when earlier they were
exported by mysqld.exe

Windows, fixes for storage engine plugin loading
after various rebranding stuff

Create server.dll containing functionality of the whole server
make mariadbd.exe/mysqld.exe a stub that is only  calling mysqld_main()

fix build