Add extra libraries to Ubuntu 18.04 runtime (with public testing of this new runtime)

[tannisroot]

Libraries without which Lutris builds won't launch if those libraries are missing in the system or won't work properly:

• libgcrypt
• libgnutls
• libldap
• libgpg-error
• libsqlite

[strycore]

If you look at the buildbot git history you'll notice that most of those libs have been removed for good reasons

[tannisroot]

well didn't that happen when we still had Ubuntu 16.04 runtime as default? Maybe it will work just fine with 18.04 libraries.

[tannisroot]

I will try and package such extended runtime myself and ask a few people from different distros to test and see if it works well.
Then, if it all goes well, we could actually bring fire and destruction upon the world make a experimental runtime package like you suggested.