Picodata / tarantool static build should be doable offline

Picodata's build process is intended to be doable completely offline after all the git submodules have been downloaded. Basically running cargo build --offline should work if there's no connection to the internet. Currently this is not working, because there are some preparatory steps for library ldap which require downloading stuff from internet presumably for tests, see:

This should be fixed. Any data that we actually need should be added either to the third-party or to the vendor subdirectory. Any data we determine to be optional (for example tests for libraries which we don't patch) should be removed from our repo.