Add spack packages for tvb-framework dependencies that are not available on spack

Spack packages are not available for some of the dependencies of tvb-framework package: pyAesCrypt and formencode. I am adding here the spack files for them, so we can have all tvb-framework functionalities available in the Lab.

requested review from @akarmas

assigned to @paulapopa

merged

mentioned in commit df364e34